constant hysteresis-band current control strategy based on the random variable bandwidth is proposed. An extra random hysteresis-band is added in the constant hysteresis-band. It is introduced for adjusting the variation of current to achieve constant switching frequency. Depending on the switch states, some information of the derivative of the current error is used for predicting an bandwidth with the random function which can widen the range of switching frequency, so as to reduce the harmonic distortion rate and decrease the switching loss. Simulation results show the effectiveness of the control strategy.