Abstract: The paper introduces the application of optic fibre voltage,current sensor in coal mine.At industrial frequency voltage of 4￣6kV and current of 100￣1000A it is verified that voltage error is less than 1% and current error less than 3% of optic fiber electric parameters sensors.It is pointed out that improving current detection accuracy is the powerful way to improve optic fiber and decrease pre amplifier noise and collect magnetic fields efficiently.