The invention belongs to the technical field of agricultural machines and particularly relates to a fixed digging device for potatoes, comprising a shovel base support, a transitional plate threadingbar, shovel blade transitional plates and digging shovels, wherein the shovel base support comprises a shovel base front plate, a shovel base back plate, shovel base weld plates, shovel blade fixing plates and shovel blade fixing holes, the shovel base weld plates are fixedly mounted at two ends of the top of the shovel base front plate, the shovel base back plate is fixedly mounted on the top ofthe shovel base front plate, the shovel blade fixing plates are fixedly mounted on the top of the shovel base back plate, the shovel blade fixing holes are formed at the shovel blade fixing plates along the left and right, the transitional plate threading bar penetrate the shovel blade fixing holes, and the shovel blade transitional plates are fastened on the transitional plate threading bar, andare arranged between the two shovel blade fixing plates. According to the fixed digging device for potatoes, service life of the digging shovels is prolonged, piling-up of soil and crushing to potatoes are avoided, and general effect of working performance is improved.