The invention discloses Brevendimonas diminuta BZC-3. The Brevendimonas diminuta BZC-3 was collected in the General Microbiological Center of China Microbiological Culture Collection Management Committee on January 15th, 2016, and the collection number is CGMCC (China General Microbiological Culture Collection Center) NO. 12070. The strain can be applied to degradation of gentamicin, and the method for degrading gentamicin refers to inoculating Brevendimonas diminuta BZC-3 to a system containing gentamicin to be cultured to realize the degradation of gentamicin. The Gentamicin degradation strain, namely Brevendimonas diminuta BZC-3 can be used for treating pharmaceutical wastes, including wastewater, waste residues and the like with gentamicin residues to reduce damages of gentamicin on the environment, humans and animals so as to solve the problem of antibiotic pollution.