The invention discloses a novel carbonyl reductase, a gene, a mutant thereof, a recombinant expression vector containing the gene and the mutant, a recombinant expression transformant, a recombinase preparation method, and applications of the carbonyl reductase and recombinase to preparation of active chiral alcohols with a chiral carbonyl compound before asymmetrical reduction. The carbonyl reductase is derived from candida glabrata, is applied to preparation of a plurality of optically-active chiral alcohols such as (R)-chloromandelic acid methyl ester, (R)-2-hydroxy-4-phenyl ethyl butyrate, (R)-4-chlorin-3-phenyl ethyl butyrate and the like. Compared with other preparation methods, a product prepared through the method has high concentration, does not require additionally or slightly adding any expensive coenzyme, has high optical purity, and has the advantages of mild reaction conditions, easiness and convenience for operating, easiness for amplifying and the like, and has a good industrial application prospect in the production of clopidogrel, L-carnitine and perindopril antihypertensive medicinal intermediates.