The invention provides a voltage balancing circuit for double rechargeable batteries. The voltage balancing circuit comprises a balancing circuit and an integrated control circuit, wherein, the integrated control circuit comprises a voltage detection module, a delay control module, a DC modulation module and a driving and amplifying module. The voltage detection module detects the voltage of the rechargeable batteries and outputs a balance start signal and a balance direction signal; the delay control module outputs a balance time control signal according to the balance start signal; and the DC modulation module determines the balancing circuit to work or stop according to the current direction on an inductor in the balance direction signal and the balance time control signal, thereby effectively controlling the rechargeable battery with the higher voltage to charge the rechargeable battery with the lower voltage, achieving the voltage balance of the rechargeable batteries and reducing the energy loss. Meanwhile, during the voltage balancing process of the rechargeable batteries, the balance time control signal of the delay control module separates the balance work time from the voltage detection time and accurately detects the voltage of the batteries during the balancing process.