Abstract: In order to ascertain the sterilization effect and influencing factors of microwave technology on freshly squeezed watermelon juice, this study firstly used Shahan watermelon juice as the research object to carry out sterilization verification analysis under three factors of different microwave frequency, sterilization treatment time, and initial temperature. Secondly, the influence of the above three factors on the physical and chemical indexes and sensory evaluation of watermelon juice was studied by the corresponding surface analysis method. The optimal solution of microwave frequency, sterilization treatment time, and the initial temperature was obtained. The single factor test results show that: under the fixed conditions of initial temperature of 30 ℃ and microwave treatment time of 180 s, the greater the microwave power, the better the sterilization effect. Under the fixed conditions of initial sample temperature of 30 ℃ and microwave power of 3 kW, with time growth, the total number of colonies decreases. Under the fixed conditions of microwave power of 3 kW and processing time of 180 s, the initial temperature has a strong tendency to weaken the influence of microorganisms. The response surface design test showed that the order of the influence of each factor on the total number of bacteria is: microwave processing time＞microwave power＞initial sample temperature. The optimal experimental conditions obtained are microwave processing time of 180 s, microwave power of 3 kW, and the temperature of 30 ℃. The results of sensory evaluation analysis show that the microwave treatment results are better than traditional water bath sterilization treatments for both the physical and chemical indicators and flavor of the juice. The results of this article can provide a certain reference and reference for the optimization of the sterilization process and technical improvement of fresh watermelon juice.