The invention discloses a novel special concrete contraction reducing type compacting agent, which relates to a novel special concrete contraction reducing type compacting agent, and belongs to the technical field of concrete admixture. The preparation method of the product comprises the following steps: preparing stock solution with deionized water, sodium sulfide solution, sulfur powder and a catalyst, wherein the catalyst is mixed solution of methoxypolyethylene glycol, dimethyl-1, 3-propylene glycol and alkylphenol ethoxylate sodium sulfide; and then preparing an inorganic waterproof contraction reducing type compacting agent for inorganic concrete with deionized water, the stock solution, triethanolamine, methoxypolyethylene glycol, dimethyl-1, 3-propylene glycol, alkylphenol ethoxylate sodium sulfide, silicate and a defoamer DF-642. The compacting agent is prepared under the low intermingled quantity, and experimental results show that when the intermingled quantity is 0.1-2 percent, the invention can effectively reduce the early contraction of the concrete, decrease the cracking risks, enhance the concrete compaction, improve the pore structure, and achieve the functions of preventing water and leakage, thereby enhancing the resistance of the concrete against physical and chemical erosion. However, the invention relates to an II type compacting agent, which has a significant effect on the reduction of the concrete contraction and is particularly applicable to the engineering field with strict requirements for concrete contraction and cracking.