The invention relates to a connection structure for a composite material and a metal piece. The connection structure comprises the composite material and the metal piece. The composite material comprises a composite material insert plate on the lower layer and a composite material tiling plate on the upper layer. A metal piece connection face is provided with grooves, and the composite material insert plate is filled into the grooves. The composite material and the grooves are subjected to one-time auxiliary vacuum forming or step-by-step auxiliary vacuum forming through tough colloid. By means of the structure characteristics of the grooves and the strip-shaped crossed metal structure, large-area connection of the composite material plates and the metal piece can be achieved. By means of the limitation to the groove angles, optimal clamping clips, chopped fiber or felt filled to gaps between the composite material plates and the metal piece and solidification of the tough colloid, connection of the composite material and the metal piece can be more stable. By means of one-time auxiliary vacuum forming or step-by-step auxiliary vacuum forming, the watertight characteristic of the structure can also be effectively ensured.