The invention provides an explosive welding method for pre-processing a rare and precious metal composite plate through severe surface deformation. The method includes the following steps that a base material and a composite material are determined, a connecting face of the base material and the composite material is cleaned and processed, severe deformation processing is performed on the connecting face, the connecting face is baked, roughness processing is performed on the connecting face, leveling processing of the connecting face is performed, and explosion welding and cladding and follow-up repair welding, leveling, edge cutting and mechanical polishing are performed, wherein a severe deformation processing method includes rolling, mechanical grinding, mechanical impacting, shot blasting or sand blasting. Before explosive cladding, the severe surface deformation processing is performed on the base material and the composite material, the connecting face can be of a multi-stage micro structure in different sizes, and the defect that cracks and the like happen easily in the explosive cladding process of rare and precious metal can be reduced; and besides, the severe surface deformation induces a large number of crystal structure defects, intermetallic compounds can be reduced, and the interface binding strength is remarkably improved.