The invention belongs to the technical field of motor machining and discloses a motor stator slot-sealing mechanism and a motor stator slot-sealing machine. The motor stator slot-sealing machine comprises a frame, a slot wedge paper carrier disc, a slot-sealing mechanism, and a stator support mechanism, wherein the slot wedge paper carrier disc, the slot-sealing mechanism, and the stator support mechanism are disposed on the frame. The slot-sealing mechanism comprises a paper feeding device for pulling slot wedge paper strips out of a slot wedge paper roll and feeding the slot wedge paper strips downwardly, a cutting-off device for cutting off the slot wedge paper fed by the paper feeding device, a molding device for extrusion molding the cut-off unformed slot wedge paper, and a slot wedge inserting device for pushing formed slot wedge paper out of the molding device and inserting the slot wedge paper into the sealed motor stator slot. The slot-sealing machine achieves automation of slot wedge paper insertion by designing the paper feeding device, the cutting-off device, the molding device, and the slot wedge inserting device in a combined way. The motor stator slot-sealing mechanism and the motor stator slot-sealing machine are compact in overall structure, simple in operation, and high in reliability.