Abstract: The paper established a mathematical model of diode-clamped type three-level shunt active power filter(APF) with three-phase three-wire,put forward a control scheme of shunt three-level APF combining with calculation of instruction current based on i_p-i_q method,predictive current control and space vector pulse width modulation(SVPWM).It also analyzed simplified three-level SVPWM control algorithm.The result of simulation and experiment showed that the scheme has good compensation effect for harmonic wave,and is suited for DSP hardware realization and main circuit protection with full-digital control,has better application prospect.