China's electricity market, which is still in the early stage of development, is in dire need of reasonable and effective price risk prevention techniques. Firstly, the SSVM-OR-EW algorithm is used to quantify the dynamic risk coefficients of individual units and the market as a whole. Secondly, the double-insurance risk prevention and control technology of "ex-ante risk prevention & ex-post risk disposal" are studied. A two-layer model of "evolutionary game-optimization clearing" is constructed. According to the dynamic risk coefficients, soften the ex-ante risk prevention, and introduce the theory of caprice to ex-post risk disposal, and construct an expert logic deduction system to further improve the price risk prevention and control. The expert logic deduction system is constructed to further explore the possibility of unit risk and provide a realistic basis for the regulatory agencies to deal with it in accordance with the regulations. Finally, an example analysis is carried out with the data of a regional spot market, and the results show that the preventive system effectively disposes of risks while avoiding the drawbacks of rigid price regulation and realizing closed-loop prevention and control.