Abstract: Due to its high capture efficiency,relatively mature technology and good adaptability,CO_2 chemical absorption technology is currently the most potential CO_2 capture technology for industrial application. However,in CO_2 chemical absorption system,absorbent is used to capture CO_2 in the flue gas,and part of the absorbent and its degradation products are discharged with the flue gas,which not only increases the loss of absorbent,and further reacts in the atmosphere to form strong carcinogen nitrate amine and nitrosamines. Therefore,it is necessary to effectively control the pollutant emission from CO_2 chemical absorption system. At present,pollutants are usually controlled by adjusting the operating parameters of the system and using pollutant control means,but there is no universal control method and the pollutant emission control target value has not been established. In this paper,three emission forms of pollutants in CO_2 chemical absorption system were introduced,including physical entrainment,gas and aerosol. The aerosol has high emission and is difficult to be controlled by traditional methods. According to the emissions measured by the research institutions,CO_2 chemical absorption systems of different scales generally have higher emissions. The mechanism of aerosol generation and growth was analyzed. The aerosol emission is mainly produced through heterogeneous nuclei,which depends on the existence of condensation nuclei and the supersaturated environment. Based on the experimental and simulation methods,the effects of condensation core of flue gas,inlet temperature of lean liquid,lean liquid load and CO_2 content of flue gas on the emission of organic amine dominated by aerosols were reviewed. The research on the emission of degradation products,including oxidative degradation and thermal degradation,was briefly introduced. Finally,the control effect,advantages and disadvantages of the current pollutant emission control methods were summarized. The traditional water washing method can effectively control the gaseous emission of organic amines. The traditional mist eliminator has a good control effect on large-size aerosol particles,but the removal efficiency of small particles is low. Although wet electric dust removal,steam injection,dry bed and other methods have certain removal effect,but the cost is high. Acid pickling can solve the problem of ammonia emission,but it is difficult to recover organic amines.Colloid gas foam method has high efficiency for aerosol removal,but there is a lack of industrial research. In the future,it is necessary to develop new control methods for pollutant emission,which can effectively reduce the emission of pollutants in the form of gas phase and aerosol,and control the industrial investment cost. This method will be the key link for the establishment of advanced carbon capture process system.