The surface of fresh cucumber was sterilized by atmospheric pressure low temperature plasma to study sterilization effect of atmospheric pressure low temperature plasma on Escherichia coli (E. coli) on the fresh sliced cucumber surface. On the basis of single factor test, a quadratic polynomial mathematical model for the sterilization rate of E.coli was established by response surface methodology to analyze the effects of processing voltage, time and pole distance, and their pairwise interactions, and the quality of cucumber was studied under the optimum conditions. The experimental results showed that E.coli on the fresh sliced cucumber surface could be effectively killed by atmospheric pressure low temperature plasma. Factors influencing the sterilization rate were in order as processing voltage>processing pole distance>processing time. The conditions were optimized as follows: processing voltage 170 V, processing time 5 min, processing pole distance 2.5 cm. the sterilization rate reached to 99.65% under these conditions, which closed to the predicted value of 99.60%, and improved the edible safety of fresh sliced cucumber. The factors, include water content, soluble solids, pH value, color, relative conductivity, malondialdehyde and Vc content of cucumber, were not significantly changed (P>0.05). The fresh sliced cucumber remained the moisture, sugar, acidity and color, as well as the cell membrane permeability and antioxidant capacity.