The invention discloses a loading and unloading device for shaft processing of a numerical control lathe. The loading and unloading device comprises the numerical control lathe, a rack, a loading bracket, an unloading bracket, a horizontal transfer mechanism and a mechanical arm assembly, wherein the mechanical arm assembly consists of a lifting air cylinder, a transposition holder mechanism, a sliding seat mechanism and a guide mechanism, and is mounted in an upper plane of the rack; the transposition holder mechanism consists of a mechanical arm seat plate, a bearing support, a gear ring, a clamping cylinder, a rotating shaft bolt, a transposition motor and a transposition motor gear, and is mounted in an upper plane of the horizontal transfer mechanism; the numerical control lathe is arranged in the rack; the loading bracket is arranged on one side of the numerical control lathe; the unloading bracket is arranged on the other side of the numerical control lathe. The loading and unloading device meets the requirements of the numerical control machine on shaft product processing, saves human resources, reduces the labor intensity of workers, reduces the processing cost and improves the production efficiency. In addition, the loading and unloading device can adapt to the requirements of modern automation mass production by being matched with a PLC (Programmable Logic Controller).