In order to improve the hydraulic control position and pressure conversion control process of upsetting direction designed in linear friction welding system and improve the position accuracy of upset direction，the principles of hydraulic control position and pressure conversion control mode were studied, and the characteristics of upsetting direction position control and pressure control and their respective controller forms were clarified. The upsetting direction position control and pressure conversion control strategy were further studied, the upsetting position and pressure collaborative control method was proposed, and the control characteristics were verified by experiments. The research result has theoretical and practical significance to improve the production efficiency and performance of the main engine.