The invention discloses a preparation method of a wet curing reaction-type polyurethane hot melt adhesive for a textile. The preparation method mainly comprises the following steps: (1) stirring and mixing polyether polyol 4000E, polyether polyol 3000H and an antioxidant, heating and warming to about 120 DEG C, dewatering for 0.5 hour when the vacuum degree is smaller than 100Pa; (2) adding a tackifying resin, continuing to warm to 135-140 DEG C, dewatering for 1.5 hours when the vacuum degree is smaller than 100Pa; (3) cooling to 87 DEG C, adding 4,4'-diphenyl methane diisocyanate and a catalyst, stirring and reacting for 2 hours when the vacuum degree is smaller than 100Pa; (4) relieving a vacuum state, adding white carbon black, quickly stirring and evenly mixing, and continuing to stir for 10 minutes when the vacuum degree is smaller than 100Pa; and (5) keeping the discharge temperature at 85-100 DEG C, quickly discharging and encapsulating, and then curing for 4 hours under the condition of 80-85 DEG C, so as to obtain a target product. The product is applied to compounding of the textile, and has excellent peel strength, short opening time, good hydrolysis resistance and good storage stability.