The invention discloses a preparation method of a structural shield integration board made of high-boron stainless steel. The problem that at present, the manufacturing cost of the high-boron stainless steel prepared through powder metallurgy is high is solved. The method comprises the following steps that firstly, high-boron stainless steel alloy powder is contained in a combined mold to be subject to generate a prefabricated green blank through a cold isostaitc pressing technology; secondly, the prefabricated green blank is put into a sintering furnace to be subjected to heating, temperature rising and heat preservation under the vacuum or H2 atmosphere to be sintered into a sintering blank; thirdly, the sintered blank is put into a carbon steel mirror frame, and the sintering blank with the mirror frame is put into a high-temperature furnace to be subject to heating, temperature rising and heat preservation to be forged into a thick plate; fourthly, the thick plate is put into the high-temperature furnace again to be subject to heating, temperature rising and heat preservation to form a thin plate with the needed thickness in a hot rolling manner; and fifthly, the carbon steel mirror frame on the thin plate is removed, and a board finished product is obtained through solution treatment and straightening. The preparing method has the advantages that process equipment is simple, the cost is relatively low, and the mechanical property of the board is excellent.