Under special working conditions such as offshore operations and moving devices, the surface of the worktable inclines under external forces, which affects efficiency and reliability of the work. An automatic hydraulic balance control system was designed based on PLC. The system consisted of PLC, man-machine interface, sensor and hydraulic pump station. The sensor was used to monitor the inclination of the working face, the test results were transmitted to PLC for analysis and calculation through Modbus-RTU, and the hydraulic system was controlled according to the analysis results, so as to realize the automatic balance of the working face. The test results show that the hydraulic automatic balancing system has fast response speed, accurate adjustment and good application effect.