The full-welded heat exchanger belongs to a partition wall heat exchanger, and the structure thereof is that two fluid passages are formed by welding two adjacent plates, and two different temperatures fluid are respectively flowed through the channels on both sides of the same plate. Each medium channel controls the flow area and the flow length through the splitter partition, so that the high temperature fluid transfers heat to the low temperature fluid through the plate, thereby achieving the heat exchange purpose. The surface of the heat exchanger is smooth and not easy to scale. Its unique corrugated design allows the fluid to generate turbulence at lower flow rates, with high heat transfer efficiency. The entire plate bundle is made of argon arc welding using bulk material. Does not use any non-metallic sealing material, so it has high temperature and pressure resistance. It can be used in extreme working conditions with an operating temperature of 300℃ and a pressure of 3.0 MPa. Corrugated plate structure with similar plate heat exchanger, with more advanced all-welding process seal, no gasket design, plus a variety of metal and alloy materials to ensure that MAX full-weld heat exchanger is suitable for temperature -195℃ to 538 ℃, working pressure from vacuum to 8.2 MPa in almost all heat exchange process applications. And its compact structure design, efficient heat transfer performance and convenient and flexible use determine the superior performance of completely replacing traditional shell-and-tube heat exchangers.