In order to solve the problem of microbial safety on the cut surface of fresh carrot, the surface was sterilized by atmospheric pressure low-temperature plasma(ATLTP) to study sterilization effect on staphylococcus aureus. On the basis of single factor test, a quadratic polynomial mathematical model for the sterilization rate of staphylococcus aureus was established by response surface methodology to analyze the effects of processing voltage, processing time and processing pole distance, and their pairwise interactions. The experimental results showed that staphylococcus aureus on the fresh cut carrot surface could be effectively killed by ATLTP. Factors influencing the sterilization rate were in order as processing voltage>processing pole distance>processing time. The conditions were optimized as follows: processing voltage 170V, processing time 5min, processing pole distance 2.5 cm. The sterilization rate reached to 92.35% under these conditions, which closed to the predicted value of 92.26%, and improves the edible safety of fresh sliced carrot. The water content, soluble solids, pH value, color, relative conductivity, malondialdehyde and Vc content of carrot were not significantly changed (P>0.05) . It is better to maintain the moisture, sugar, acidity and color of carrot, while maintaining the cell membrane permeability and antioxidant capacity.