Abstract: To improve gangue emission efficiency of gangues and coal gangues to discharge gangues smoothly and orderly, the PLC atuomatic loading and unloading control process and method are introduced besed on the PLC design process,and an approach for the automatic handing and transportation is prepared.Then, the trapezoidal pattern and command procedures of the control system are programmed, so as to send the command procedure to the debug system by PLC programmer for installation and utilization.By the PLC automatic loading and unloading control lines, the situations that the relay what is mostly used to send and receive control signals at current are not reliable; the system often shows errneous signals and wrong operation, can be greatly improved, and the production efficiency and safety can be significanlty increased.Meanwhile, the service life of the motor vehicle is extended, and the labor intensity of workers reduced, owing a certain social benefils.

Key words: Automatic loading, PLC,Trapezoidal pattem, Loading and transportation of gangues