A power-on reset signal generating apparatus and a voltage detection circuit thereof are provided. The voltage detection circuit includes a latch circuit, a pre-charge circuit, a pull-down switch and an output stage circuit. The pull-down circuit is turned on or cut off according to the power-on reset signal. The pre-charge circuit operates a pre-charge action according to a power-on reset signal or a power supply voltage. The output stage circuit receives the power supply voltage, based on the power supply voltage, generates a detection output voltage according to an input end of the inverter and the power-on reset signal.