The invention discloses a pellet mixture moisture control device and method, and relates to the technical field of iron and steel smelting. The device comprises a mixing machine, a first belt machine,a second belt machine, a water fetching pipe, an adjusting valve and a flow meter. The first belt machine is arranged at one end of the mixing machine, the second belt machine is arranged at the other end of the mixing machine and different from the first belt machine, the water fetching pipe is connected with the first belt machine, the adjusting valve is arranged on the water fetching pipe, theflow meter is arranged on the water fetching pipe, and the flow meter is located above the adjusting valve. The technical problems that in the prior art, pellet mixture moisture fluctuation is large,moisture cannot be stably controlled within a target range, and stable operation of a pelletng section is not facilitated are solved, and the technical effects that moisture is stably controlled within the target range, follow-up pelleting section requirements are met, and therefore pellet mine yield and quality stability is improved are achieved.