Abstract: Seven National Petrochemical Industrial Parks will be built, which are located either in the coastal areas or islands. It is important to strengthen marine environment protection during the petrochemical park operational period. Post environmental impact assessment (PEIS) is one of the important means to check the environmental management level and find the environmental problems during the operational period. At present, one of the most common PEIS methods is environmental factor analysis. However, it is still rarely applied in the petrochemical park as a whole. The method is based on evaluating resource, environment and management. Based on the analysis of the marine environment in China and the analysis of the petrochemical park seause, and combined the characteristic of PSR model, the evaluation indicator system of marine environmental impact is put forward. The system is divided into framework layer, solution layer and index layer, with a total of 25 assessment indicators. The system can provide ideas for the petrochemical park marine environmental management research in the future, At the same time, the evaluation scheme of various evaluation indicators such as assignment and weight is established. At last, a case study of a petrochemical park in Dalian was carried out to verify the effectiveness of the evaluation.