本文分析了传统安全网排量及排量系数计算方法存在的问题，在考虑阀瓣影响因素的安全阀排量计算模型基础上，提出了安全阀排量系数计算公式。通过试验研究，发现安全阀排虽系数是一个与压力比有关的参量，随压力比的增大而减小，安全阀一般处于亚临界流动状态。通过对压力比影响排量系数的机理探讨，澄清了传统方法的错误观点。试验结果表明．本文公式的计算误差不超过8％，是规范计算误差的五分之一。 This paper analyzes the existing problems in the calculation of displacement and displacement coefficient of safety net. Based on the calculation model of safety valve displacement considering the influence factors of valve flap, the calculation formula of safety valve displacement coefficient is proposed. Through experimental research, it is found that although the coefficient of safety valve row is a parameter related to pressure ratio, it decreases with the increase of pressure ratio, and the safety valve is generally in the subcritical flow state. Through the discussion of the mechanism that the pressure ratio affects the displacement coefficient, the mistaken view of the traditional method is clarified. The results showed that. The calculation error of this formula does not exceed 8%, which is one-fifth of the standard calculation error.