Aiming at the problems of unstable valve spindle movement and jamming failure easily occurring during the opening of the triple eccentric butterfly valve,the operating torque and action characteristics of the triple eccentric butterfly valve were studied.The internal flow field state,dynamic hydraulic torque and its coefficients of the triple eccentric butterfly valve under different opening degrees and differential pressure were simulated and calculated using the finite element simulation software Fluent,and the simulation results accuracy was verified through experiments.Using the operating torque equation of triple eccentric butterfly valve,the experimental valve was numerically calculated and its operating torque variation with the opening degree was analyzed.Finally,the simulation platform AMESim was used to model the single-acting pneumatic actuator system and to analyze the influence of the operating torque on the opening valve action time and the stability of the butterfly plate.The results show that:with the increase of differential pressure,the maximum value of dynamic hydraulic torque shifts to small opening degree and reaches the maximum value in the 60° to 75° opening degree interval;the larger the differential pressure of butterfly valve is,the longer and more unstable the valve spindle action time are,and the action time of triple eccentric butterfly valve increases by 4.4% and 10.7% under 0.1 MPa and 0.3 MPa differential pressure,respectively;increasing the cylinder diameter and the spring elasticity coefficient can increase the stability of action.