The invention relates to the technical field of slag machining, the field of marine environmental protection, and the field of fishery industry basic facilities, in particular to a preparation method for an artificial fish reef concrete material with slag as a main raw material. The preparation method for the artificial fish reef concrete material with the slag as the main raw material is characterized in that the slag which is machined through a tightly-closed method technology is respectively used in rough aggregate, fine aggregate and binding material raw materials, and mineral waste residues, cement clinker, and flue gas desulfurization gypsum are mixed into binding materials. Compared with the prior art, the preparation method has the advantages that infiltration quantity of the slag is not lower than 75% and the slag is suitable for construction of an artificial fish reef with a large volume, a large hole rate and a complex structure, the strength of the slag can reach to 54-82MPa so that construction of the artificial fish reef can be satisfied and compact of sea tide and sea waves is resisted; the difficulties that the slag is deposited in a bulk mode, land is occupied and environment is polluted are resolved; solid waste such as the mineral waste residues and the desulfurization gypsum are further applied, and the use ratio of the solid waste can reach above 97%, and the preparation method for the artificial fish reef concrete material with slag as the main raw material has obvious resource benefits, environmental benefits, economical benefits and social benefits.