Abstract: In order to improve the transient response of the switching converter indiscontinueous conducting mode (DCM), a differential extrapolation control method is proposed based on the charge balance principleusing Boost convertor as an example. This method uses the variation of sampled output voltage to carry on an extension, which indicates the load influence on the output capacitor charge, and then obtains the current control quantity by the balance algorithm. Compared with the traditional charge balance principle based current control (CBPC), this method reduces control delay and the transient instability caused by the approximate of load information.The method also providesreferencefor thedesign of DCM controllers.The response waveforms of CBPC control and DE control are comparedby Boost prototype, when input, load and reference voltage are disturbed. Among these experiments, the response is better when using DE control proposed in this paper.