Abstract: The invention provides a pump unit for a miniature cleaning machine, and belongs to the technical field of cleaning machines. The problem that an existing pump unit is frequently maintained is solved. The pump unit for the miniature cleaning machine comprises a motor, a pump shell, a plunger and a transmission assembly, the plunger and the transmission assembly are arranged in the pump shell, a reset spring enabling the plunger to always have the upward moving trend is arranged in the pump shell, the transmission assembly comprises a pump main shaft, an eccentric shaft and a ball bearing, one end of the pump main shaft is in transmission connection with the motor, and the other end of the pump main shaft is in transmission connection with the eccentric shaft.