EARPHONE CHARGING SYSTEM AND CHARGING METHOD THEREOF

An earphone charging system and a charging method thereof are provided. A charging circuit of an earphone device converts an output voltage provided by a charging device into a charging voltage to charge an earphone battery when the output voltage is higher than a preset voltage. The earphone device or the charging device adjusts the output voltage to switch between a first voltage and a second voltage, so as to perform data transmission between the earphone device and the charging device, wherein the first voltage and the second voltage are higher than the preset voltage.