A motor control apparatus providing an exercise resistance and an auto-rewinding function mainly employs a microprocessor to operate with a current detection feedback loop and a motor rotation speed detection loop for precisely controlling a quick random operation of a motor such that an axle of the motor can quickly control a loss braking unit and a power driving unit based on the existence of an external force, and the motor can automatically switch to an electric generator output mode (for providing an exercise resistance) or an electric machine output mode (for providing the automatic rewinding function).