The invention discloses a method for treating a zinc-containing waste liquid. The method comprises the following steps of (1) mixing the zinc-containing waste liquid with lime milk and precipitating the mixture to obtain a liquid-solid mixture; (2) concentrating the liquid-solid mixture to obtain overflow containing zinc hydroxide precipitate and underflow containing calcium sulfate; and (3) filtering the overflow containing the zinc hydroxide precipitate to obtain zinc hydroxide and a filtrate. According to the method, a non-toxic reagent, namely the lime milk is directly used as a precipitant to precipitate zinc, compared with the prior art, the production cost of the zinc per ton is saved by not less than 2000 yuan, the direct yield of the zinc is up to 96%, the effect is remarkable, and the method is suitable for industrial production and application.