In this study, R60702 plate and TA2 plate were successfully bonded together by explosive welding. The microstructure, element diffusion, microhardness changes near the bonding interface before and after heat treatment were investigated utilizing optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and microhardness tester. The mechanical properties and fracture morphology in initial and heat treated states were examined as well. The results demonstrate that after explosive welding, the explosively welded bonding interface shows a wavy appearance, obvious deformations and short element diffusion. The microhardness values decrease gradually with the increasing distance from the interface due to the diminishing deformations. After heat treatment, a diffusion layer and recrystallization occur in the microstructure. The overall microhardness values, the tensile strength and shear strength decrease while the plasticity and ductility are improved compared with the initial state. The explosively welded R60702/TA2 composite plate shows a good bending performance after heat treatment.