The Schmidt^® semi-welded plate heat exchanger is composed of corrugated plate pairs each of which includes two plates subjected to laser welding, with one side sealed through welding and the other side sealed with gaskets. The semi-welded plate heat exchanger is designed based on the advantages of removable and welded plate heat exchangers, which ensures excellent sealing performance, reduces the risk of medium leakage and facilitates the removal for maintenance, thus reducing the maintenance cost and difficulty. Therefore, the product can better meet the heat exchange requirements.