The invention belongs to the field of PCHE heat exchangers, and particularly relates to a PCHE heat exchanger core structure design test prototype. The test prototype comprises an upper cover plate, aflow channel system and a lower cover plate which are sequentially arranged from top to bottom, wherein the flow channel system comprises one or more flow channel units, the flow channel units comprise end plate areas on the two sides and flow channel areas in the middles, notches are formed in the end plate areas, the two ends of the flow channel areas are correspondingly located in the notches,moreover, gaps are reserved between the flow channel areas and the bottoms of the notches, the upper plate surfaces and the lower plate surfaces of the end plate areas are connected together with theupper cover plate and the lower cover plate respectively, and the gaps, the upper cover plate and the lower cover plate jointly form a cavity. The PCHE heat exchanger core structure design test prototype has the beneficial effects that the limit load of a PCHE heat exchanger core structure can be accurately measured through the test prototype which is simple in structure, economical and practical, and a reference is provided for the design of the PCHE heat exchanger core structure.