The invention provides a method used for manufacturing a copper alloy composite steel plate; the substrate material is carbon steel plate and the composite plate is copper alloy plate; the manufacture method comprises the manufacture steps as follows: I matching: copper alloy composite plate and normal carbon steel plate which comply with the national standard and usage technical requirement according to the detection are combined in pairs according to the requirement of final products; II: stress troughs of 8-10mm deep and 10-12mm wide are arranged at the circumference of the copper alloy composite plate; III: grinding the surface: oxides and sundries on the explosive combination surface of the substrate and the composite plate are removed; subsequently, a protection layer is uniformly coated on the contact surface of composite plate and dynamite; IV explosive welding: the composite plate and the substrate are supported by copper fulcrum or aluminium fulcrum and welded together by virtue of explosive welding. The combination rate of the manufacture method of the copper alloy plate and the composite steel is more than 99%, with the hardness of HB130-150, thus completely meeting the requirement of copper motor plate on the hardness.