Abstract: To solve the problems of weak durability and low bearing capacity of current concrete strengthening technology, double shear tests were conducted based on the technical for strengthening concrete structures with reactive powder concrete and bar mesh (RPCBM). The shear strength, failure mode and load-displacement curve of each specimen were evaluated, and the effects of roughness, pin rate and bar mesh specification on the interfacial stress strength of RPCBM reinforced old concrete structure were discussed . The results show that the shear strength and ductility of RPCBM reinforced concrete structure are greatly improved, and the interface has good bonding performance. Within a certain range, the shear strength of bonding interface increases with the increase of roughness; the shear strength and ductility increase with the increase of pin rate. In addition, the bar mesh specification is an important factor for improving the interface ductility. The shear strength model of bonding interface was established to calculate the interface bond strength of RPCBM reinforced concrete. The shear strength formula of RPCBM reinforced ordinary concrete (OC) interface was proposed, and the test results were consistent with the theoretical analysis, which provides a theoretical basis for the selection of reinforcement materials and improvement of construction methods in engineering practice.