A control system for dynamically adjusting an output voltage of a voltage converter includes a signal calculation circuit, a pulse width modulator, a voltage converter, a nonlinear calibration circuit and a signal converter. The signal calculation circuit, the pulse width modulator, the voltage converter and the signal converter form a long-tail loop. The signal calculation circuit simultaneously receives a target value and a detection value from the signal converter to generate an error value for adjusting the output of the pulse width modulator. The voltage converter and the nonlinear calibration circuit form a local pulse-squashing loop. Pulse widths of an input signal to the voltage converter can be timely and effectively calibrated and controlled, thereby decreasing power consumption of the voltage converter and providing an effective protective mechanism.