Abstract: In order to improve the performance of 11JF-1.2 cotton straw feeding-fermentation machine and ensure the quality of output materials, the working parameters of the machine were optimized. By carrying out single-factor tests and orthogonal tests and using Design-Expert 10.0 software, response surface optimization analysis was carried out on the data obtained from the test. The test results show that the contribution rate of each factor to the evaluation index, from largest to smallest, was spindle speed, material density, and heater temperature. Through the optimization and solving function in the software, the optimal combination of working parameters was spindle speed at 5 r/min, material density at 176.5 kg/m~3, and heater temperature at 39.5 ℃. According to the obtained optimal parameter combination, the average moisture content variance is 1.009, and the average fermentation temperature is 36.9 ℃. After optimization, the performance of the machine was significantly improved and met the design requirements.