The invention discloses a preparation method of a cangrelor intermediate. The product formed by the ring-closing reaction of ethyl cyanoacetate and thiourea under alkaline conditions is reacted with trifluoropropane under alkaline conditions, and then undergoes nitration reaction, After reduction reaction, carry out ring-closure reaction with formic acid again; After the product of generation carries out chlorination reaction, product carries out condensation reaction with 2-(thiomethyl) ethylamine under alkaline condition; Under the action of TMSOTF, it reacts with 1,2,3,5-tetraacetyl-β-D-ribofuranose, and the product is hydrolyzed under alkaline conditions to obtain the cangrelor intermediate. The method of the present invention does not need to use silica gel column chromatography, which greatly saves the process cost; and does not involve carbon disulfide, fuming nitric acid or concentrated sulfuric acid in the preparation process, and does not have any danger; in addition, no precious metal hydrogenation reducing agent is used, which not only reduces The cost is low and the operation risk is reduced; the method of the invention is easy to operate, safe and reliable, and suitable for large-scale industrial production.