An automatic frequency hopping method is provided for use with a wireless device. The wireless device could transmit data in two or more communication frequency bands. According to the counts of successful data transmission in respective communication frequency bands, the reasons of communication failure are analyzed. According to the reasons of communication failure, the automatic frequency hopping method discriminates whether a frequency hopping procedure is performed. Since the frequency hopping procedure is performed when a proper frequency hopping condition is satisfied, the automatic frequency hopping method could achieve the power-saving purpose and avoid the wireless communication interference with other wireless devices.