Abstract: A transfer device includes an automated guided vehicle, a positioning platform, and a positioning transmission mechanism. The automated guided vehicle is provided with a supporting frame; the positioning platform is arranged on the supporting frame. The positioning transmission mechanism includes a first locking assembly, a second locking assembly, and a first driving assembly connected to the first locking assembly and the second locking assembly. The first locking assembly and the second locking assembly are arranged on two opposite sides of the positioning platform at an interval in a first direction in a horizontal plane. The first driving assembly is configured to drive the first locking assembly and the second locking assembly to move toward or away from each other, such that the first locking assembly and the second locking assembly cooperate to fix a piece-to-be-transferred.