As Class 1 drilling fluid processing devices in the slurry purification system, shale shakers adopt imported exciting motors that facilitate duplicate or triplicate drilling fluid purification and also enjoy application in bottom flow vibrating screening with slurry cleaners. It is characterized by high vibration intensity, increased screening area, adjustable screen box angle, compact structure, and high performance. 1. As Class 1 drilling fluid processing devices in the slurry solid phase control system, shale shakers are used to separate the large volume of drilling cuttings mixed in the slurry when returning from the shaft, so as to prepare for entering the secondary separators. 2. Shale shakers are designed based on the vibration theory of the linear motion trajectory generated by the screening surface. Angle a between the motor midperpendicular and the shaker causes off-set of excitation power in Direction X caused by the rotation of both exciting motors in opposite directions. The summation of excitation power in Direction Y leads to the reciprocating movement of the entire screen box as well as the repeated up-cast of slurry on the sieve surface in the identical direction, followed by recurring free fall at a forward distance. The majority of solid particles mixed in the slurry are screened out when the slurry passes the sieve and enters the tank, thus facilitating the slurry purification.