The invention relates to a process for preparing reinforced hard liquor yeast at low temperature in winter, and belongs to the technical field of preparing yeast at low temperature. The invention provides a process of reinforcing prepared yeast and increasing the yeast forming rate and the high-quality yeast rate in a low-temperature environment (the temperature is lower than 15 DEG C). A wheat and barley mixture is used as a raw material, according to the formula, wheat and barley are mixed by the weight ratio of 9:1, a solid composite functional microbial agent accounting for 0.6% of the total weight of the wheat and the barley is added into the raw material formula, and the composite functional microbial agent is composed of pure rhizopus preparation and an esterification monascus strain by the weight part of 1:5. The yeast forming rate and high-quality yeast rate during yeast preparation under the low temperature condition are obviously increased by adding the reinforcing functional microbial agent, the liquor yield and high-quality liquor rate are greatly increased, and the problems that in the prior art, yeast cannot be prepared in winter, and prepared yeast in spring and autumn cannot meet production requirement of liquor brewing in an enterprise are solved.