The invention relates to the technical field of spinning yarn, in particular to a preparation method of semi-combing antimicrobial blending doubling yarn. The preparation method of the semi-combing antimicrobial blending doubling yarn aims at increasing the yield, reducing the production cost and improving the antimicrobial performance. The method includes the steps of (1) selection of raw materials, wherein the yarn is prepared from 60-70% of 90S mercerization australasian wool, 5-10% of cashmere and 25-30% of china-hemp, and the total matching ratio of the 90S mercerization australasian wool, the cashmere and the china-hemp is 100%; (2) dyeing treatment of the 90S mercerization australasian wool and the cashmere, wherein the 90S mercerization australasian wool and the cashmere are matched under the room temperature according to a bath ratio of 1:8-1:12, and moreover 0.5-1 g/L glacial acetic acid, a 0.5-1 g/L levelling agent Albegal B, 0-3% of reactive dyes from the shallow to the deep for wool and the like are added; the preparation method of the semi-combing antimicrobial blending doubling yarn, by adopting a mode of doubling whole hemp purchased form exterior with plush blending yarn, the production efficiency is improved, the yield is substantially increased, and the production cost is reduced.