The invention discloses a preparation method of a nitrogen-rich modified desulfurization and absorption material. According to the preparation method, raw coal and semi-coke particles are taken as main raw materials, and a bonding agent and deionized water are used as an auxiliary molding agent; the preparation method comprises the steps of sequentially carrying out mixing, molding, carbonizationand steam activation on the raw materials to obtain a porous carbon material; finally, carrying out heat treatment by using a nitrogen-containing reagent so as to form the porous absorption material with high desulfurization efficiency. The preparation method provided by the invention is simple in technological process and mild in operation conditions; furthermore, the desulfurization rate of theobtained porous absorption material is stabilized to be 92% or above.