In order to provide accurate parameters for rudder delay phase compensation, a real-time calculation method for rudder delay time of rolling missile was proposed. A/D conversion module is added to the hardware of the computer on the missile to realize the acquisition of the rudder feedback signal, the zero-crossing time of the control command and the rudder deflection angle is calculated according to the periodic zero-crossing characteristics of the control command and the rudder deflection angle of the rolling missile, and the delay time of the rudder engine is calculated according to the zero-crossing time difference. The results show that the delay time calculation module is added in the missile computer software, and the delay time calculation accuracy is improved by linear interpolation, moving average filtering and other methods to meet the guidance and control requirements of the spinning missile.