Composition used for preparing laminated board, laminated board and preparation method of laminated board

The invention provides a composition used for preparing a laminated board, the laminated board and a preparation method of the laminated board. The composition comprises 50-55 parts by weight of chlorinated polyvinyl chloride, 39-46 parts by weight of polyvinyl chloride, 2-3 parts by weight of chlorinated polyethylene or alpha-methylstyrene low polymer, 2-3 parts by weight of acrylic ester copolymer or MBS (Methacrylate Butadiene Styrene) resin. The composition can solve the problems that the melt viscosity in the laminated board material is large, the flowability is alleviated and the laminated board can not be processed easily.