A signal converter with an overcurrent protection mechanism comprises a pulse width modulation (PWM) unit, a timing processing and multi-level conversion unit, an overcurrent detection unit, and a pulse width control unit. The PWM unit converts an analog signal into a pulse signal. The timing processing and multi-level conversion unit receives the pulse signal and converts the pulse signal into a multi-level digital signal. The overcurrent detection unit has a reference voltage terminal outputting a reference voltage. The overcurrent detection unit receives the multi-level digital signal and converts the multi-level digital signal into a detection voltage. The pulse width control unit compares the detection voltage with the reference voltage and outputs a control signal to the PWM unit. Thereby is formed a feedback mechanism to adjust the output voltage and prevent the succeeding circuit from being damaged caused by overcurrent of the pulse signal.