Stacking device, loading machine and loading system

The invention provides a stacking device, a loading machine and a loading system, and relates to the technical field of loading. The stacking device comprises a pushing assembly, a stacking platform and a conveying assembly, wherein the pushing assembly is movably connected to the stacking platform, the conveying assembly is arranged at the middle part of the stacking platform, the conveying assembly comprises a first conveying piece and a second conveying piece both extending in the second direction, the first conveying piece and the second conveying piece are rotationally connected to the stacking platform, the first conveying piece is close to the end part, in the first direction, of a conveying line and is used for receiving goods, the second conveying piece is arranged on one side, inthe first direction, of the first conveying piece, the second conveying piece comprises a plurality of rolling parts which are coaxially arranged, and the plurality of rolling parts are rotatably connected to the stacking pl