A small vibrating screen type tuber crop harvesting machine comprises a machine frame, a digging mechanism, a transmission mechanism, a cleaning sorting mechanism and a walking mechanism, wherein the digging mechanism, the transmission mechanism, the cleaning sorting mechanism and the walking mechanism are arranged on the machine frame. The digging mechanism is located at the lower front position of the machine frame, the cleaning sorting mechanism is located right behind the digging mechanism, and the transmission mechanism is located in the middle of the machine frame and is respectively connected with the digging mechanism and the cleaning sorting mechanism. The transmission mechanism comprises a front shaft, a rear shaft and a pull rod which are all fixed on the machine frame, wherein the front shaft is provided with a main chain wheel, a side chain wheel I and a side chain wheel II, the side chain wheel I and the side chain wheel II are located on two sides of the main chain wheel, the rear shaft is provided with a side rear chain wheel I and a side rear chain wheel II, the side chain wheels respectively drive corresponding side rear chain wheels through transmission chains, and the rear shaft is connected with the pull rod through an eccentric wheel to drive the cleaning sorting mechanism to swing vertically in a reciprocating mode. A vibrating screen is used in the tuber crop harvesting machine, the length of the harvesting machine is reduced, walking space in operation is guaranteed, and due to a fixed type digging shovel, digging depth is stable, and the tuber crop damage rate is lowered.