A caster active control system that is mounted on a suspension including a strut assembly for automatically adjusting a cater angle of a wheel of a vehicle, may include a fixed frame that is fixed to a vehicle body, a movable frame slidably mounted on a bottom of the fixed frame and configured to reciprocate in a front-rear direction of the wheel, a strut mount unit fixed to the movable frame and connected with an upper end of the strut assembly, and an operation module disposed between the fixed frame and the movable frame and engaged with the movable frame, wherein the operation module is driven by a motor to move the movable frame in the front-rear direction of the wheel.