The invention discloses a method for reducing expression enzyme activity of beta-glucosaccharase of aspergillus niger by adopting the phosphate-induced promoter, belonging to the field of gene engineering. The method comprises the following steps: (1) constructing the DNA fragments composed of the phosphate-induced promoter or DNA sequences containing the phosphate-induced promoter, DNA sequences expressing antisense mRNA complementary to beta-glucosaccharase mRNA, and terminator subsequences to an expression vector; (2) transforming the recombinant vector constructed in the step (1) to aspergillus niger; and (3) adding phosphate into a culture medium, and culturing the aspergillus niger strain into which the recombinant vector is transformed. According to the method provided by the invention, the phosphate-induced promoter is adopted for regulating the transcription of antisense mRNA complementary to beta-glucosaccharase mRNA, so that the translation amount and expression activity of beta-glucosaccharase are effectively reduced, further, the cellulase system combination expressed by aspergillus niger is optimized, and the efficiency of the cellulase system for degrading cellulose is exerted to the maximum.