Abstract: This article introduces a type of positioning device with orientation. It can be used for positioning of the big part on the automatic transfer line, which is not easy due to large inertia. The device is driven by a cylinder within which a sliding plate is assembled. The sliding plate pushes the positioning plate thus part positioning is performed. The big area of sliding plate in the enclosed cylinder provides capability of bearing heavy duty and gaining high rigidity. By adjusting the thickness of positioning plate, the accurate position of big parts can be automatically controlled which ensures high reliability and high production rate. The structure may be applied multiply to adapt to various specifications of parts.