The invention discloses a wide-channel plate type heat exchanger and a heat exchanger particle swarm optimization structure design method, and belongs to the technical field of heat exchanger design.Six variables of a trapezoid boss on the surface of a single-layer heat exchange plate are extracted for forming structure parameters, and the design range is determined; an orthogonal method is adopted, and 25 sets of typical heat exchanger plates with different structures and operation conditions are generated; through Soliworks, the single-layer heat exchange plate is generated, and on the basis of Fluent numerical simulation software, a heat exchange nusselt number and the pressure drop of the corresponding heat exchanger plate structure are obtained; according to the obtained sample set,a heat exchange nusselt number and pressure drop comprehensive criterion relation model of a heat exchanger plate is fitted; the maximum heat exchange nusselt number and the minimum pressure drop serve as optimization targets, particle swarm optimization is adopted, and optimizing is carried out to obtain the structural parameters of the optimal heat exchanger plate; and the heat exchanger has theadvantages that the heat exchanger is suitable for finding shape parameters obviously affecting flowing and heat exchange characteristics of the plate type heat exchanger, under the condition that core parameters are continuously distributed, the shape parameter distribution range with the best heat exchange effect and meanwhile the minimum pressure drop losses can be searched.