Aiming at the phenomenon of high hydraulic impact at the end of the initial propping stage of the hydraulic support and the resulting reliability reduction of the hydraulic support,taking the main valve of ZF17000/27.5/42D hydraulic support directional valve as the research object,based on the analysis of the structure composition,working principle and the mechanism of hydraulic impact,a hydraulic impact suppression method was proposed to control the flow by controlling the flow area of the valve port.In view of the current situation of using a single spring to complete the spool resetting of the existing directional valve,the flow gradient of the hydraulic support in the spool closing process was reduced by setting parallel reset spring,thus the hydraulic shock phenomenon at the end of the initial support stage was alleviated.AMESim software was used to build the directional valve model,and the dynamic characteristics of the directional valve were simulated.The flow,pressure,velocity and spool displacement laws of the main valve were obtained.The results show that compared with the original scheme,the improved scheme reduces the peak flow and velocity peaks,and the flow gradient and velocity gradient decrease by 9.91% and 9.87%,respectively,then the phenomenon of hydraulic shock at the end of the initial support stage is effectively alleviated.