Anaerobic digestate of pig manure has the characteristics of continuous and quantitative poly. The effluent of anaerobic digestate contains a large amount of ammonia nitrogen. The processing capacity of the two stage air-recirculation stripping process is difficult to meet industrial requirements for treatment of anaerobic digestate of pig manure. Gas flow rate, liquid flow rate and gas-liquid ratio were chosen as running parameters of continuous air-recirculation process. The running parameters were studied and the process was optimized by response surface methodology. The initial ammonia nitrogen concentration of anaerobic digestate was (1444±37)mg/L. Ammonia nitrogen removal rate could reach (66.81±0.24)% when the gas flow rate, liquid flow rate and gas-liquid ratio were 530L/h, 445 mL/h and 2036, respectively, which was the best optimal parameters combination. The model optimized by response surface methodology could well analyze and predict ammonia nitrogen removal efficiency of continuous air-recirculation process for treating anaerobic digestate of pig manure. Gas-liquid ratio was the limiting factor for the process of continuous air-recirculation stripping process. According to perturbation plots of ammonia removal efficiency, the influence order from large to small of the three selected parameters for removal ability of ammonia nitrogen was gas-liquid ratio, liquid flow rate and gas flow rate. The process could be used to strip and recover ammonia nitrogen from anaerobic digestate of pig manure. It could reduce foaming tendency of treated fluid and the foams could be broken more quickly than the two stage air-recirculation stripping process. The process could reduce the height of stripping tower and investment of engineering. The result can provide some references for the continuous processing for anaerobic digestate of pig manure.