Fenitrothion was a kind of organophosphorus insecticides.Its neurotoxicity and genotoxicity to aquatic organisms, mammals and other non-target organisms have attracted widespread attention, so it is necessary to study its degradation in water. In this paper, an organophosphorus pesticide degradation strain G1 (identified as oligotrophomonas) was selected as the material to explore the degradation characteristics of fenitrothion in water. The results show that: the degradation rate of strain G1 for 20 mg·L^-1 fenitrothion were reached 90% within 1 h The degradation half-life is only 17.2 min The optimum temperature and pH for fenitrothion degradation by strain G1 was 37℃, and 7-8, respectively; the degradation efficiency was positively correlated with the initial inoculation amount of strain G1 and negatively correlated with the initial substrate concentrations; Under the condition of 5 mmol·L^-1 metal ions, K⁺ and Na⁺ could promote the degradation of fenitrothion by strain G1, while Co²⁺, Mg²⁺, Ca²⁺, Cr³⁺, Fe³⁺ could inhibit the degradation. Meanwhile, fenitrothion could be degraded to 3-methyl-4-nitrophenol and O,O dimethyl phosphorothioate by strain G1. The results provide technical support for the environmental microbial degradation and remediation of fenitrothion pesticides.