Abstract: The heat treatment experiments on TMCP processed bridge steel Q370 qD and stainless steel 316 L explosive welding composite plate at different temperatures were carried out. The effects of heat treatment temperature on the technological state of substrate TMCP were evaluated through testing and observing its performance and microstructure changes. The results show that when the microstructure of the substrate remains unchanged in the heat treatment process of 316 L/Q370 qD(TMCP) composite plate, the impact properties, yield strength, yield strength ratio, intergranular corrosion and other properties of the composite board can meet the design requirements.