In order to study the effect of interfacial agent on the bonding properties of wet joints, the optimal dosage of silica fume in the interfacial agent of silica fume cement paste was determined through mechanical property test. Then, the splitting tensile strength test, three-point bending test and shear strength test were conducted to explore the use of ordinary cement paste, cement paste with optimal dosage of silica fume and epoxy resin as interfacial agent. Effect on bonding properties of wet joints. The results show that the mechanical properties of the cement paste are the best when the optimal content of silica fume is 8%. The effects of different interfacial agents on the bonding properties of wet joints are analyzed from the tensile and shear angles, and the order from the largest to the smallest is: epoxy resin interfacial agent > 8% silica fume cement interfacial agent > ordinary cement interfacial agent > no interfacial agent. It is concluded that the interface agent of ordinary cement paste has little improvement on the bonding property of wet joints, while the interface agent of epoxy resin and 8% silica cement paste has obvious improvement on the bonding property of wet joints.