In order to study the effect of the valve port structural parameters of the main valve of pilot operated relief cone valve on the anti-cavitation properties of the valve port to cavitation,based on the CFD method,the Mixture two-phase flow model and Schnerr-Sauer cavitation model were used,the structure parameters of the valve port were changed and the variation law of total pressure and gas volume fraction of each valve port was analyzed,the anti-cavitation properties of the valve port was improved.The results show that the pressure restoration in the off-flow region of the valve port is even more effective after extending the inner cone face of the valve sleeve towards the inlet end;additionally,the annular groove structure has a greater effect on the anti-cavitation properties of the valve port.After comparison,it is concluded that the 45° starting edge inclination of the annular groove structure provides optimum anti-cavitation properties,while keeping the axial position,length and depth of the annular groove structure unchanged.