According to the process characteristics of a 1651cm (65 inches) tire vulcanizing machine,the electrohydraulic servo direct drive pump controlled hydraulic system was used to control the pressure in the pressure cylinder in the moldclosing pressureincreasing and pressure keeping links.By establishing a mathematical model of pressure control of the pressure cylinder and inputting parameters of tire vulcanizing machine and its hydraulic system, the response curve of pressure control was simulated. The pressure control experiment was carried out with the hydraulic station pressure cylinder of the vulcanizing machine, and the related parameters such as overshoot, steadystate error and response time of the system were analyzed. The experimental results show that the pressure control system of pressing cylinder has good dynamic performance, accuracy and stability, and can meet the technological requirements of the moldclosing pressureincreased and pressurekept on tire vulcanizing machine.