The elevating counterbalance valve is installed in the hydraulic circuit of the truck crane elevating system,which plays the role of load maintaining and controlling the speed of load movement.Based on the analysis of the structure and function of the counterbalance valve used by a crane,for the complex flow of its main spool,a method was adopted to calculate the flow area of the throttle groove and the main spool separately and then integrate it,and the opening-flow area curve of the main spool was obtained.The simulation models of the check valve and the main spool in the counterbalance valve were established by using the AMESim software.By comparing the simulation and experimental results of the flow and pressure characteristics of the counterbalance valve,it is proved that the opening-flow area curve obtained by this calculation method can accurately reflect the performance characteristics of the counterbalance valve.The key factors affecting the flow and pressure characteristics of the counterbalance valve were explored,which could provide model support and reference ideas for the optimization design of the counterbalance valve.