The invention relates to a light and simple scallion digging machine and a working method thereof. The light and simple scallion digging machine comprises a frame and is characterized in that a powerdevice is fixed on the frame, the power device drives power wheels through transmission devices so as to allow the scallion digging machine to move, two symmetrically-distributed scallion digging devices are fixed on the frame, each scallion digging device comprises a chain transmission mechanism, and a plurality of evenly-arranged thin and long teeth are fixed to each chain transmission mechanism; when the scallion digging machine moves, and the thin and long teeth are inserted into soil and rotate along with the chain transmission mechanisms under the effect of the soil so as to complete a digging action lifting soil backwards by using the bending resistance of the thin and long teeth. The scallion digging machine is simple in structure, low in production cost, energy-saving, environmentally friendly, convenient to use and suitable for cell operation.