In order to realize the accurate flow control of proportional valve,a kind of large flow control valve driven by a lead screw to drive the pilot spool was designed.The pressure required to open the spool was established in the control chamber of the main valve and the flow connection was set up,so the proportional control of the flow was realized;the AMESim platform was used to make simulation analysis.The step response characteristics show that when at the beginning,the main spore moves,and when t=0.5 s,it remains at the opening displacement of 5.8 mm,and the main valve outlet flow rate is 285 L/min,which meets the design standard.The opening and closing characteristics show that the main spool velocity has a significant lag after t=0.05 s until the main spool opens.The characteristics of position matching between stages show that the main spool also follows the step signal to complete the fast response:when the ramp signal is turned on,the main valve moves with the pilot valve,but there is still displacement response lag and 0. 5 mm steady-state error is formed.