An earphone line control device includes a power supply management unit, a filter unit, a control unit, a first resistance, a first diode, a first switch, a second resistance and a second switch. A first end of the power supply management unit, a first end of the filter unit, an end of the first resistance, and an end of the second resistance are all connected to a power supply; the other end of the first resistance is connected to an anode of the first diode, a cathode of the first diode is connected to an end of the first switch, the other end of the second resistance is connected to an end of the second switch, the other end of the first switch and the other end of the second switch are both connected to ground; a first end and a third end of the control unit are respectively connected to the cathode of the first diode and the other end of the second resistance, a second end of the control unit is connected to ground, a fourth end of the control unit is connected to the other end of the filter unit; a second end of the power supply management unit is connected to ground, a third end of the power supply management unit is connected to the control unit. When the first switch or the second switch is turned off, the control unit outputs a preset coded pulse signal.