Metal-surface sandwich composite plate

The utility model relates to a metal-surface sandwich composite plate which comprises two metal panels and a sandwich layer arranged between the two metal panels. Lap-joint openings are arranged at the two sides in the width direction of the composite plate, the main body part of the sandwich layer between the two lap-joint openings is a prefabricated core material plate, the two side faces in the width direction of the core material plate form a polyurethane foaming space with lap-joint opening surrounding parts of the two metal panels stretching out of the corresponding side of the core material plate, and the parts of the sandwich layer at the positions of the two lap-joint openings are polyurethane core materials formed by polyurethane foaming agents filled in the foaming space in foaming and solidifying manners. As the main body part of the sandwich layer adopts the core material plate, the comprehensive cost of the composite plate is reduced. The lap-joint openings are formed by padding PU in foaming an