The plate heat exchanger consists of plates, sealing gaskets, fixed compression plates, movable compression plates, compression stud nuts, upper and lower guides, and front pillars. The plate is hung on the positioning screw by the hook, and the sealing gasket is adhered by the bonding agent at the sealing groove of the two plates. The gasket acts as a sealing on the one hand to prevent the medium from leaking out, and on the other hand, a certain gap is formed between the two plates to form a medium flow path. The entire unit is pressed with movable end caps and fixed end caps at both ends for sealing. The plate gap is determined by the contact point of the plate and the thickness of the spacer. Small gap with high heat transfer coefficient, suitable for cleaning liquid, large gap used to treat liquids with particles and fibers.