In fact, there are some problems in macro coordination, distribution structure and service efficiency in the purchase of large instruments and equipment. The reason is that the purchase demonstration does not play its due role in the allocation of resources. This article introduces the mechanism design theory in the field of economics, establishes the coordination mechanism of incentive compatibility and information interchange, carries out the comprehensive reform of elements sorting, process re-engineering and data driving to the demonstration work of equipment purchase, and then designs a four-in-one linkage path of “argumentation, budget, procurement and use”. The practice shows that the demonstration reform of large instruments and equipment purchase based on the perspective of mechanism design theory is helpful to solve the problems of structural stagnation and low efficiency in the purchase of large instruments and equipment in universities, and promote the efficiency of capital use and management efficiency.