With the improvement of China's industrial manufacturing capacity and people's living standards, more and more plastic products appear in people's daily life. Because of the use and loss of plastic products, as well as the participation of plastic products in related industrial activities, the amount of micro plastics entering the environment is also increasing, both ecological health and human health are threatened. At present, the problem of plastic pollution in the environment is becoming increasingly serious worldwide. In order to reduce the harm of plastic pollution to the environment, this paper conducts a plastic ecological risk assessment on the sewage generated in the production process of a plastic industry, explores the potential risks of plastic pollution to the natural environment, can deeply understand the current situation of plastic pollution in the environment, and then uses SMBR process to treat plastic production sewage, analyzes the removal rate of CODcr. The results show that:, SMBR has a good removal effect on micro plastics, which provides a technical reference for the implementation of plastic pollution prevention.