A nonlinear smooth zero return method of a carrier rocket servo mechanism comprises the steps of determining the start nonlinear return-to-zero moment and nonlinear return-to-zero moment of each servomechanism, then obtaining nonlinear return-to-zero moment of each servo mechanism and corresponding time parameters, and finally calculating to obtain a corresponding return-to-zero coefficient according to the time parameters of each servo mechanism, so that the swinging angle of an engine of each servo mechanism after correction is obtained, and the nonlinear smooth return-to-zero of the servomechanism is completed.