The present invention provides a pillow to prevent snoring. The pillow includes a base and a mobile seat A shift control assembly shifts the mobile seat between positions and includes a motor, gear set and drive assembly. The shift control assembly also contains a motor output control module for controlling the rotational cycle of output end of the motor. The mobile seat shifts to different positions prior to and after shift based on the set value of the rotational cycle, and this rotational cycle is accurately controlled. The head position or posture happens through different positioning of the mobile seat prior to and after shift, thus helping to stop the snore with improved applicability.