The invention discloses a shell position change mechanism of a mower head shell feeding device. The shell position change mechanism of the mower head shell feeding device comprises two parallel position change installation plates, the upper plane of one position change installation plate is sequentially provided with a servo motor fixing base and two lead screw bearing blocks, a servo motor is installed on the servo motor fixing base, a rotary shaft of the servo motor penetrates through the servo motor fixing base and is fixedly provided with a lead screw through a coupler, the other end of the lead screw sequentially penetrates through the two lead screw bearing blocks, the lead screw is sleeved with a lead screw nut, the lead screw nut is fixedly provided with a lead screw nut fixing block, and the lower plane of the lead screw nut fixing block is fixedly provided with a position change guide plate. The shell position change mechanism of the mower head shell feeding device further comprises displacement assemblies which are symmetrically arranged on the upper planes of the two position change installation plates and identical in structure. In this way, the mechanism can take the place of manual work to exchange positions of workpieces.