The invention relates to a comprehensive performance evaluation method of a diffusion-welding compact type heat exchanger plate structure. Same cross-section channels are used for same plates. On thepremise that the channel structure meets the strength calculation requirement, area effective utilization rates of straight channel and specially-shaped channel plates are calculated; with same testing conditions, the heat-transfer and flowing property indexes of the straight channel and specially-shaped channel plate structures are tested; and comprehensive performance evaluation is carried out on the specially-shaped channel plate structure by using the effective area utilization rate of the straight channel and the heat-transfer and flowing property indexes as references. According to the invention, the method can be used for guiding an optimized design of the diffusion-welding compact type heat exchanger plate structure; and harmonic unification of the energy conservation and high efficiency and the high compactness of the diffusion-welding compact type heat exchanger is realized.