The invention relates to the field of building materials, and particularly relates to a heat insulation board capable of blocking hot and cold bridge, and a preparation method thereof. At present, heat insulation materials used for outer walls are not ideal. The technical solution adopted by the invention is as follows: raw materials comprise, by weight, 40-45 parts of cement, 8-35 parts of redispersible rubber powder, 0.1-0.5 parts of cellulosic fiber, 10-15 parts of polyphenyl particles, 20-25 parts of fly ash, 5-10 parts of defoaming stone, 1-5 parts of light calcium carbonate, 1-5 parts of heavy calcium carbonate, 10-15 parts of a heat insulation material and 20-50 parts of expanded glass beads. The raw materials are distributed for three times and shaped in one time. The heat insulation board has the following beneficial effects of good flame retardant performance, incombustiblity, good heat insulation effect, good cohesiveness and high strength. Due to the board shape, the heat insulation board is convenient for construction and use, is reasonable in price, has the same service life with buildings, is suitable for being used by outer wall surfaces of various buildings, and has good economic benefits and social benefits.