Acetoxime was synthesized by one-step oxidation in a continuous flow micro-channel reactor with special micro-structure, using acetone, ammonia and hydrogen peroxide as raw materials, titanium silicalite（TS-1） over catalyst and tertbutanol as solvent. The effects of concentration of hydrogen peroxide, ammonia, hydrogen peroxide, solvent, co-catalyst and temperature on ammoximation were investigated. The results showed that under conditions of outlet pressure of AFR micro-channel reactor system was 5 bar, temperature at 100 ℃, and catalyst concentration was 8 g/mol(acetone unit), molar ratio of ammonia/H2O2/tertbutanol/ acetone=3:1.1:6:1, concentration of H2O2 and ammonia were 70 and 25 wt% respectively, concentration of co-catalyst was 3 mg/mol(acetone unit), residence time was 72 s, conversion of acetone reached 80%, selectivity of acetoxime reached 97%, and yield of acetoxime reached 77%. AFR micro-channel reaction system had significant advantages, including small liquid holding capacity, short residence time, strong mass transfer and heat transfer, which strengthened coordination effect between reaction material and catalytic system, reaction rate of ammoximation was also increased considerably, essence safety of acetone ammoximation caused by decomposition of hydrogen peroxide was solved effectively, and green, safe and efficient of acetone ammoximation was realized.