Composite insulation board

The utility model discloses a composite insulation board which comprises a panel, a back plate, a fireproof insulation material layer filled between the panel and the back plate, an inserting port and a sealing rubber strip, the inserting port comprises an inserting male head at the left end and an inserting female head at the right end, the inserting male head is provided with a protruding part, a first nailing surface is formed on the top surface of the protruding part, and a second nailing surface is formed on the bottom surface of the protruding part. An inner groove is formed in the plugging female head, a drainage groove is formed in the inner groove, the back plate exceeds the plugging female head and extends outwards to form a second nailing surface, the protruding part is inserted into the inner groove, and the screw is inserted into the second nailing surface from the first nailing surface; and the sealing rubber strip is filled in a gap between the plugging male head and the plugging female head. A