A pumping unit motor belt micro-adjustment device belongs to the technical field of pumping unit belt adjustment. With the pumping unit motor belt micro-adjustment device adopted, the shortcomings of the prior art are overcome. The pumping unit motor belt micro-adjustment device is formed by connecting a shaft, bearing seats, a supporting plate, supporting columns, a bottom plate, a lifting rod, a hand wheel, a lifting plate and pin holes, wherein the supporting plate is fixed at the upper ends of the supporting columns, the two bearing seats are fixed on the supporting plate, the shaft is sheathed in the middle of the two bearing seats, the bottom plate is fixed at the bottom ends of the two supporting columns, the lifting plate is fixed in the middle of the two supporting columns by passing fixing pins through the pin holes, the lifting rod is installed in the middle of the lifting plate, the top end of the lifting rod is fixed on the supporting plate, the hand wheel is sheathed in the middle of the lifting rod, and the lower side of the lifting rod is connected with a screw rod.