The invention relates to the field of gene engineering and inheritance engineering, in particular to a high glucose tolerance beta-glucosidase mutant and a gene and an application thereof. The mutant is that amino acid at 315 position of beta-glucosidase is mutated from histidine 'H' to arginine 'R', it is measured that the glucose tolerance of the mutant is 400 mM higher than that of wild types, and the specific enzyme activity basically remains unchanged; when daidzin is used as a substrate, under the same condition, the enzyme activity promotion effect of glucose on the mutant and wild types is 212% and 163% respectively. By using the mutant, the glucose tolerance of the beta-glucosidase can be greatly improved, and the transformation and absorption of soybean isoflavones in monogastric animals are effectively promoted, thus the feed utilization rate and animal growth performance are improved.