The invention discloses a method for blowing hydrogen in cover annealing, which is mainly used for producing stainless steel. The method comprises three processes, namely a heating stage, a heat preserving stage and a cooling stage. The method is characterized by blowing the hydrogen in the heating stage and not blowing the hydrogen in both the heat preserving stage and the cooling stage, specifically, blowing the hydrogen when starting heating, wherein the hydrogen flow rate is 5 cubic meters per hour; blowing the hydrogen for 10 hours; stopping blowing the hydrogen when a temperature reaches 840 to 850 DEG C; heating by using coal gas in the heat preserving stage; keeping a constant temperature of between 840 and 850 DEG C for 10 to 16 hours; and entering the cooling stage, namely, blowing by using a blower for 10 hours for cooling, and discharging when the temperature lowers to 245 DEG C. By making an experiment of the method in the Hot Rolling Mill of Shanxi Taigang Stainless Steel Co., Ltd., the hydrogen consumption for annealing a ton of steel is reduced to 1.5 cubic meters from 3.5 cubic meters, and the effect is obvious.