As the hydraulic system pressure of TBM tunneling machine is easily disturbed by hydraulic oil pressure and temperature change, it is difficult to precisely control the pressure. The tunneling mechanism of the test bed of hybrid tunneling mechanism built in the previous study was taken as the research object. The pressure of the system was controlled by adjusting the proportional relief valve opening with PID closed-loop control mode using Siemens S71500 PLC logic controller. The pressure of the hydraulic system was fed back to the PLC by the detection and transmission of the pressure sensor. The closed-loop pressure control system was established to control the system pressure of the continuously varying propeller and the support device. The accurate, stable and automatic control of hydraulic pressure of TBM tunneling mechanism test bed was realized. In order to protect the hydraulic cylinder and related hardware equipment of the experimental platform，the mathematical model was established by using the Simulink in MatLab，and the PID parameters such as Kp, Ki and Kd were optimized，the performance of the test bed of hybrid tunneling mechanism was improved.