Abstract: The accident warning indicators were optimized by the analytic hierarchy process. By calculating and comparing the weights of each indicator, the heavier indicator was selected to form the water pollution accident warning indicator system. On the basis of this, the framework of the pollution sources online monitoring and early warning indicator system was initially constructed in the light of the general production and pollutant discharge situations of the industrial enterprises. Taking the delayed coking process of one enterprise as an example, the above method was applied to analyze the environmental pollution that may occur in the production process, calculate the weights of each indicator using the analytic hierarchy process, and determine the construction process of the early warning indicator system. The indicators that need to be monitored online were finally determined for the delayed coking devices, including COD_Cr, petroleum hydrocarbon, ammonia nitrogen, sulfides and phenols.