Abstract: The heat treatment experiments have been carried out on T2 and Q345R explosive welding composite plate at series temperatures, and the changes of its structure and properties are observed. The results show that the heat treatment temperature has no obvious effect on the shear strength, tensile strength and elongation of T2-Q345 clad plate. When the temperature is below 600℃, the clad grain size grows slowly, and the thickness of heterogeneous full-phase microstructure at the interface has little change compared with that of the explosive state. When it is above 600℃, with the increase of temperature, the grain size of clad layer grows rapidly, and the thickness of dissimilar metallographic structure at the interface increases rapidly.