The invention discloses a real-time control method for denitrification by an enhanced circulating activated sludge method, which belongs to the field of biological denitrification of sewage and is suitable for advanced treatment of urban sewage. The effect of circulating activated sludge method on nitrogen and phosphorus removal is not ideal. The steps of the present invention: open the agitator in the main reaction zone at the same time as entering the water, and carry out the denitrification process under the anoxic condition, and stop stirring when a maximum value appears on the pH value curve and an inflection point appears on the ORP curve; Oxygen is supplied to the mixed solution to degrade organic matter and nitrify nitrogenous compounds, and stop aeration when a minimum value appears on the pH curve; repeat the above steps until the end of the water inflow stage, and react with the aerobic aeration stage end of period. The following process is similar to the traditional CAST method. It enters the sedimentation, drainage, and idle stages in turn, repeating all steps in turn and discharging sludge regularly. The whole process is completed by a real-time control system, which is easy to operate, low in cost, strong in impact load resistance, and not prone to sludge bulking.