An equalizing charge circuit comprises a first input end, a second input end, a third input end, an output plus end, an output minus end, a detection circuit U1 and a flyback DC-DC converter 10. The junction of a drain of an N-MOS (N-channel metal oxide semiconductor) transistor Q and a primary winding NP of a transformer B is further connected with an anode of a diode D1, a cathode of the diode D1 is connected with the third input end, and a capacitor C is parallelly connected between the second input end and the third input end. The output plus end is connected on the anode of the batter pack, and the output minus end is connected on the cathode of the battery pack. When the detection circuit detects that voltage of a battery cell is larger than a set value, the converter 10 starts working, charge current to the battery cell is extracted and returned to charge the chatter pack, energy generated by leakage inductance of the flyback converter can be used for charging a previous battery cell, and accordingly equalizing charge of the battery pack is realized; when the detection circuit U1 composed of a single chip microcomputer is utilized, an infrared receiving head is added to synchronously adjust a set value, and equalizing discharge can be realized. The flyback circuit is high in reliability, simple in composition, low in cost, high in efficiency and easy to maintain.