In this paper， the inactivation kinetics of potassium sorbate-assisted high pressure thermal sterilization (HPTS) on Bacillus subtilis spores were studied. First-order kinetics model， Weibull and Log-logistic kinetics models were used to fit the inactivation curve of B. subtilis spores by potassium sorbate-assisted HPTS. By analysis of precision factor (Af)， bias factor (Bf)， root mean square error (RMSE)， coefficient of determination (R2)， In the three models， Log-logistic Kinetic model fitted best the spore sterilization effect of potassium sorbate-assisted HPTS (R2=0.986). When potassium sorbate (0.2 g/100 mL) assisted HPTS (600 MPa， 75 ℃， 25 min)， the inactivation effect was the best， and the spore inactivation was 6.10 lg(CFU/mL). Potassium sorbate assisted HPTS treatment was applied to the inactivation of spores in muskmelon juice， it was found that the browning degree was significantly reduced， after 28 days of storage， the absorbance of potassium sorbate (0.1 g/100 mL) assisted HPTS (600 MPa， 75 ℃， 25 min) at 420 mn reached 0.093， The absorbance of the HPTS-treated control sample was 0.058. Scanning electron microscope was used to observe the microstructure of Bacillus subtilis spores in muskmelon juice before and after treatment， and it was found that the morphological structure of the spores changed after treatment. In conclusion， potassium sorbate assisted HPTS has significant application value.