Abstract: In the current drilling process of hydrological wells，there are relatively low level processing and integration.And the introduction and innovation of new technologies，methods and processes are not sufficient.In the drilling of hydrologic well，the mud returned to the ground from the bottom of the well contains a large amount of rock cuttings and sand particles，which are mainly treated by the natural settlement by artificial sand bailer at mud pit and sedimentation tank，with lower efficiency. In order to realize the automation and modularization of drilling equipment and improve the construction efficiency，an automatic mud circulation purification device control system with green exploration and hydrogeological drilling was developed according to the complicated geological and climatic environment of Qinghai Province，including remote control subsystem， near-end control subsystem and mud heating cycle subsystem.In order to improve the anti-interference performance of the control system and increase its reliability，the hardware of the system selects PLC as the control core.The hardware and software for the mud purification device are designed with modularization and reliability in the control system.In practical application，this system has the characteristics of convenient transportation， high reliability and good adaptability.

Key words: Green exploration, Hydrogeological drilling, Mud circulation purification, Control System, PLC, Automatic control