The invention discloses a sliding mode control method for a servo motor with measurement delay output. The method comprises the following five steps of: 1, analyzing and establishing a servo motor system model; 2, designing a delay observer for a servo motor system; 3, designing sliding mode control over the servo motor; 4, checking tracking performance, and regulating parameters; and 5, finishing the design. A delay-observer-based sliding mode control method is provided for the servo motor system, and is used for controlling the rotating angle of the servo motor. By the control method, the stability of a closed loop system is ensured, a speed sensor is not required, the problem of signal delay of an angular position sensor is solved, and application in engineering practice is facilitated. The method has high practical value and broad application prospect in the technical field of automatic control.