Microbial dewaxing of crude oil is an efficient and simple method. In order to further improve the paraffin degradation rate of microorganisms, two strains L and K were used to form paraffin degradation mixed bacteria, and their degradation conditions were optimized. The factors affecting the degradation of mixed bacteria (culture temperature, initial pH value of culture medium, salt concentration, and V（L strain ）/V（K strain）) were determined by orthogonal experiment and single factor experiment. Box-Behnken method was used to design four?factor three?level experiment and response surface optimization, and a mathematical model was established to explore the best conditions for the degradation of paraffin by mixed bacteria. The experimental results showed that the influence of four single factors is as follows: V（L strain）/V（K strain）>culture temperature>salt concentration>initial pH value of culture medium. Their primary term, secondary term and individual interaction term had significant influence on the paraffin degradation rate. The optimal experimental operating conditions for the mixed bacteria to degrade paraffin were determined as follows: culture temperature 37.2 ℃, initial pH value of culture medium 7.3, salt concentration of culture medium 1.2%, ratio of mixed bacteria V（L strain）/V（K strain）=1.0∶1.6, and paraffin degradation rate 58.67%. The mixed bacteria were used to act on crude oil under the optimized conditions, and the biodegradation rate was 41.38%,have good application prospects.