Abstract: Aiming at the problem of column stalling during the lowering process of palletised hydraulic strut, the balancing circuit is improved based on the externally controlled constant pressure speed control valve, and the load bearing characteristics of the column under load are investigated. The simulation model of hydraulic support balance circuit was established by AMESim software to simulate the work-ing process of the column , and changed the structural parameters of the externally controlled constant pressure speed control valve to analyse the load-bearing characteristics of the column as well as the flow characteristics of the externally controlled constant pressure speed control valve.The results show that: when the column is impacted, the safety valve opens to unload; when the column goes down, the balancing circuit works to prevent the column from stalling.Reducing the diameter of the damping hole and the area of the regulating piston of the externally controlled constant pressure speed control valve can enhance the response speed of the system, the stability of the balancing circuit can be improved, and get the suitable load bearing characteristics of the column.