The invention discloses an LED driving circuit. The LED driving circuit comprises a PWM control unit, and a rectifying unit, a filtering unit, a first switching unit, an energy storage and follow current unit and a secondary filtering unit which are connected in sequence, wherein the PWM control unit samples from an output end through a sampling unit to control the first switching unit to be switched off and switched on repeatedly; when the first switching unit is switched off, the energy storage and follow current unit discharges to a load; the LED driving circuit is characterized by comprising a detection unit and a second switching unit; the second switching unit is connected with the filtering unit and the secondary filtering unit; and the input end of the detection unit is connected with an alternating current power supply while the output end is connected with the PWM control unit and the second switching unit and used for detecting input current frequency and outputting a signal to control the first switching unit and the second switching unit to be switched off or switched on. Two parallel switching units are arranged on the filtering unit and the secondary filtering units, and the detection unit detects the frequency of the input alternating current to control the two switching units to be switched off or switched on, so that the LED can be applicable to high-frequency and low-frequency alternating currents at the same time, and the replaceability of the lamp tube is improved.