The invention discloses an energy-saving plate heat exchanger, and belongs to the technical field of heat exchangers. The energy-saving plate heat exchanger comprises a heat exchanger body, wherein the heat exchanger body comprises a heat exchange core and a heat exchanger fixing frame which is cooperatively arranged on the outer side of the heat exchange core to achieve a fixation effect; the heat exchange core consists of a group of laminated streamline integrally reinforced heat exchange plates. By using the technology, the heat exchanger has the characteristics of large pressure bearing capacity, high heat transfer coefficient, small pressure drop, small material flow resistance loss, compact structure, light weight, small occupied space, convenience in area and flow combination, sensitivity in temperature control, large operation elasticity, convenience in disassembly and assembly, long service life, strong universality of parts, wide selectable materials, easiness in implementation of large-scale production and the like, can be widely applied to novel heat exchangers for heat dissipation of closed spaces such as wind power generation, communication or electrical control cabinet and ventilation and energy-saving after heat recovery of air conditioning places.