Abstract: In order to find out and evaluate the dominant risk factors of petrochemical plants, to realize the control and management of safety production risksat source, and to meet the requirements of high efficiency of safety production risk control of petrochemical plants, through establishing petrochemical plant accident risk impact model, using the method of the decision-making test and evaluation laboratory method from the perspective of "modern accident causal chain theory" , it was found that risk factors such as man, machine (thing) are controlled by management factors. Then, based onthe three indexes of process stability, process stability correction and unplanned shutdown, the model of the petrochemical plants' smoothness was established, and the stability rate of the plant was tracked and counted.The model was analyzed and verified by an example. The results showed that the stability model of petrochemical plants could quantify the control effect of the dominant factors of accident risk and show the risk characteristics of petrochemical plants at different stages.It can be used as an early warning index and safety management performance index to improve the safety management level of the petrochemical plants.

Key words: decision-making test and evaluation laboratory method, dominant accident risk factor, petrochemical plant, safety management, plant stability