| Two strains of salt-resistant propoxur-degrading bacteria CS1 and CS2 were isolated from the waste water treatment tank of Hali (Changde) Pesticide Chemical Co., ltd., and identified as Acinetobacter sp. through morphological characteristics, physiological and biochemical identification and 16S rDNA sequence analysis. The suspensions of CS1 and CS2 strains in the logarithmic growth stage were compounded into mixed bacterial agents according to the volume ratio of 1∶1, 1∶1.5, 1∶3, 1.5∶1, 2∶1, 2.5∶1 and 3∶1, respectively. Results showed that when the liquid volume ratio of CS1 and CS2 suspensions was 1.5:1(M6), the degradation rate of propoxur was the highest, reaching 72.68%. M6 was embedded with sodium alginate (SA)-activated carbon, polyethylene glycol (PVA)-activated carbon and PVA-SA-activated carbon. A degradation rate of 73.22% was observed when the strains were embedded in PVA-SA-activated carbon. The orthogonal test was used to optimize the 4 main factors that affect the degradation efficiency of propoxur (propoxur mass concentration, medium salinity, temperature and pH). The optimal combination of the 4 factors for degradation of propoxur by M6 include propoxur mass concentration of 200 mg/L, salinity of 3%, pH 6.5 and temperature of 30 ℃, and the degradation rate of propoxur was up to 77.34%. Degradation of propoxur by immobilized mixed bacteria M6 was effected mostly by temperature, followed by propoxur mass concentration, salinity and pH.