The complete inrush current elimination depends on the veracity of the residual flux prediction for transformers. The precedent methods cannot satisfy the increasingly strict engineering requirements. Considering the chopping current and shunt capacitor influence on residual flux, a method for predicting residual flux based on the dynamic Jiles-Atherton hysteresis model is proposed in this paper by calculating the track of core hysteresis loop. The programmable power supply is designed to simulate the voltage before and after de-energization and re-energization of transformer, which shows the validity of the method proposed.