With the development of society and economy, the process of urbanization is accelerating and its scale is also expanding. As a result, the available land is continuously reduced and the location of urban sewage plants is getting closer and closer to the residential areas. In recent years, all kinds of deodorant technologies have also been in the research and development, application, progress, and biological deodorant as a new type of green technology with its economic, practical, operational advantages have been greatly promoted. The paper briefly introduces the research progress of biofilm technology for removal of odor from sewage treatment plants. First, the characteristics of sewage treatment plant odor and hazards Smelly material is a substance that causes a wide variety of smelly organs. Smell substances generated during the sewage treatment process consist mainly of carbon, nitrogen and sulfur. Only a few odorants are inorganic compounds such as ammonia, phosphine and hydrogen sulphide; most odorants are organic, such as low molecular weight fatty acids, amines, aldehydes, ketones, ethers, halogenated hydrocarbons and aliphatic, Aromatic, heterocyclic nitrogen or sulfide. It is noteworthy that these substances are with active groups, prone to chemical reactions, especially oxidation. When the active group is oxidized, the smell disappears, the biological deodorant process is based on this principle. Stench produced in urban sewage is widely distributed and has a great impact on the human body mainly in the respiratory system, circulatory system, digestive system, endocrine system, nervous system, mental state and other aspects of harm. Second, the basic principles of biological deodorant The basic principle of biological treatment odor is the use of microorganisms to dissolve the malodorous substances dissolved in water in the body itself, through the metabolic activity of microorganisms to make it a degradation process. The substrate is eventually decomposed by microorganisms into inorganic acids, forming an acidic environment that is detrimental to the life of spoilage microorganisms and fundamentally degrading substances that produce malodorous gases during decomposition. Microbial deodorization can be divided into three processes: 1. Malodorous gas dissolving process, that is, from the gas phase to the liquid phase; 2. The malodor components in aqueous solution are absorbed by microorganisms, that is, the odor dissolved in water is absorbed by the microorganism through the cell wall and cell membrane of the microorganism, while the malodor dissolved in water adheres to the microorganism first, and the extracellular enzyme secreted by the microorganism is decomposed into soluble Material, then penetrate cells; Into the microbial cells of malodor components as nutrients for microbial decomposition, utilization, so that pollutants can be removed. Third, the main method of biological deodorant According to the existing forms of microorganisms in deodorization, the treatment methods are mainly divided into biofiltration and bio-absorption methods. Biofilm deodorization technology is a combination of these two methods and can effectively remove malodorous substances such as sewage treatment plants. Biofiltration Biofiltration deodorant is currently the most studied, the most mature technology, the most widely used method of biological deodorant. The deodorization method is under suitable conditions, so that the collected exhaust gas through the microorganism-filled filler, the smelly material is first absorbed by the filler, and then by its microorganisms oxidative decomposition of carbon dioxide and water, which smell removed. Deodorization process, the growth of microorganisms on the solid carrier to undertake the important task of material conversion, microbial growth requires adequate organic nutrients, so the solid carrier should contain A certain concentration of organic matter. At the same time, in order to maintain the activity of microorganisms, it is necessary to create a good living environment for it. During the operation, attention should be paid to control the temperature, humidity, pH, nutrients and other indicators. 2. Biological absorption method Biological absorption method (also known as biological washing method) more use of activated sludge method, the first malodorous ingredients transferred to water, and then contaminated water and then microbial treatment. By gas-liquid contact is divided into two forms: aeration and washing. Aeration is similar to the biological aeration of sewage treatment plants, except that it is injected into activated sludge instead of air with odor. The equipment used is usually an aeration tank with an air volume of 0.1-1 mm / s. The method is applicable to different kinds of malodorous gases and has good effect. The removal rate is related to sludge concentration, pH, dissolved oxygen (DO) and aeration intensity. Washing method is the use of microorganisms, nutrients and water consisting of microorganisms to absorb liquid waste treatment, this method is suitable for absorbing soluble gas. Absorption of exhaust gas mixture of microorganisms and then aerobic treatment to remove liquid absorbed pollutants, the treated absorbent can be reused. In the biological scrubbing process, the microorganisms and their nutrient ingredients are present in the liquid and the contaminants in the gas are degraded by the microorganisms after they have been transferred to the liquid by contact with the suspension. Fourth, the biofilm deodorant technology in the sewage treatment plants and other aspects of the application Uses up-flow anaerobic sludge bed reactor (UASB) can effectively remove methionine methylthiopropanol odor, after two series of UASB treatment, the removal rate of 100%, but also the smell of wastewater disappear. Hydrogen sulfide and ammonia gas were treated by the improved biological deodorization trickling filter tower. The deodorization performance of NH3 and H2S in the pilot-scale modified biotrickling filter and the interaction between them were investigated. The experimental results show that, The device has good removal efficiency for H2S and NH3. The removal rate is 99.2% when the volumetric load of H2S is 68.2g / (mh) under the condition of the circulating liquid spray volume of 10L / s and the gas flow rate of 400L / s. NH3 volume load of 10.53g / (mh), the removal rate of 99.5%. The interaction between H2S and NH3 has no obvious effect on the removal efficiency of both. Similarly, high-quality concentrations of NH3 had no effect on H2S removal, and even high-quality concentrations of H2S had no effect on NH3 removal. Biofilm method to treat malodorous gas H2S, they used PVC elastic three-dimensional packing for aerobic biological desulfurization research results show that: biological hanging film fast, domestication time is short, the impact of the self-load capacity is strong, at airspeed 100 ~ 200h-1, sprayed water is 1000 ~ 1500L / (mh), H2S mass concentration <1200mg / m, the desulfurization rate of more than 90%. Biofilter process development for biogas waste gas, development of bio-deodorizing fillers, efficiency of H2S and NH3 processes and industrial applications. The monitoring results show that the developed bio-deodorization technology has the advantages of simple process, convenient operation, low cost, no secondary pollution and high treatment efficiency. The highest H2S treatment efficiency can reach more than 99% and the NH3 treatment efficiency can reach more than 86%.