The invention belongs to the technical field of production of copper foil coated laminated boards and particularly relates to a preparation method of a laminated board with a low dielectric constant. According to the preparation method, bismaleimide, polyphenyl ether and a filling are respectively modified, so that the intermiscibility of various materials of a resin system is increased, the permeability of glass cloth is improved, the laminated board with the low dielectric constant is prepared, the difficulty and cost of a production process are lowered, and meanwhile, the performance and yield of the laminated board are increased.