In order to reduce the switching stress and loss of APF， and to enhance the APF power rating for lower pressure switch devices， this paper presents a three-phase three-wire three-level APF based on vector mode one-cycle control during 30°～390°. The main circuit of APF is based on diode-clamp three-level topology. The vector mode one-cycle control strategy is employed. The mathematic model and control object equation of the proposed APF are established， and system stability and design of PI regulator are investigated in detail. In addition， the difference and relation of the vector mode one-cycle control between 30°～390° and 0°～360° are compared. Finally simulation and experiments are implemented for the proposed APF to operate under balanced and unbalanced conditions of three-phase power supply. Simulation and experimental results show that the proposed APF can compensate the harmonics and reactive currents commendably and effectively， and verify the feasibility and validity of the proposed control strategy.