Disclosed is a wireless microphone system having a rapidly optimized MP3 audio encoder and decoder, capable of reducing the amount of calculation without losing voice to minimize power consumption and complexity of the system, and a method for controlling the microphone system. The rapidly optimized wireless microphone system comprises a transmitting part including an MP3 audio encoder, an FEC encoder, a modulator, a PN spreader, a high-frequency modulator, a power amplifier, a first controller, for converting an audio signal inputted through a microphone into an MP3 audio signal, FEC-encoding, and PN-spreading the MP3 audio signal, and then modulating the signal, to transmit it; and a receiving part including a low-noise amplifier, a high-frequency demodulator, a PN despreader, a demodulator, an FEC decoder, an MP3 audio decoder, an audio interface, an oscillator, a PLL circuit, and a second controller, for receiving the signal transmitted from the transmitting part, PN-despreading, FEC-decoding, and MP3-decoding the received signal, and then converting the signal into the original audio signal, wherein the MP3 audio encoder does not use psycho-acoustic modeling and, accordingly, performs quantization at a bit rate higher than a predetermined first bit rate without driving an outer repetitive loop of a repetitive loop required for the psycho-acoustic modeling, to thereby convert the audio signal inputted through the microphone into the MP3 audio signal.