The present invention is to provide a dynamic power control circuit for a wireless communication device, which comprises a power detector, a comparator, a low pass filter and an adder disposed between a radio frequency auto-gain control circuit and an antenna thereof. A reference voltage is imposed on the adder to enable the power detector to detect and output signal voltage to the comparator which compares the received voltage with a specified received voltage limit and outputs a reference voltage to the low pass filter for filtering out the noise of the reference voltage and outputting it to the adder. The adder then adds the reference voltage and the specified reference voltage, and outputs the result to the radio frequency auto-gain control circuit for controlling the output power corresponding to the strength of the received signals.