Lightweight fireproof insulating composite board and preparation method thereof

The invention discloses a lightweight fireproof insulating composite board and a preparation method thereof. The composite board comprises expended and vitrified microspheres, dry powdery aluminosilicate gel material, mineral high-modulus elastic fiber, dry powdery additive and composite micro-bubble agent. The lightweight fireproof insulating composite board has excellent fireproof safety, overcomes the defects of poor fireproof performance due to the use of an organic material serving as lightweight aggregate, fall and melt drop caused by serious deformation at a high temperature so as to generate personnel injury and environmental pollution caused by harmful gas produced at the high temperature, can effectively synthesize all advantages of the traditional board, integrates the advantages of all boards, has the advantages of good insulating effect, stable structure and same service life as a building, and also has the effects on energy conservation, pollution resistance, economy and the like.