The invention discloses a circulation-free three-phase double-Buck full-bridge inverter and a control strategy thereof, and belongs to the technical field of power electronic converters. The inverteris composed of two DC input voltage sources (VH, VL), twelve switching tubes (Sa1-Sa4, Sb1-Sb4, and Sc1-Sc4), eight diodes (Da1, Da2, Db1, Db2, Dc1, Dc2, DP and DN), six filter inductors (La, Lb, Lc,Lfa, Lfb and Lfc) and three alternating-current loads (Za, Zb and Zc). According to the invention, only by use of one inverter, it is achieved that two independent direct-current input sources supplypower for the alternating-current loads, and the functions of the two single-input inverters are achieved. The circulating-current-free three-phase double-Buck full-bridge inverter provided by the invention is free of bridge arm straight-through and switching tube body diode reverse recovery problems, and can work in a fixed-frequency circulation-free mode under a proposed control strategy, so that the reliability and the efficiency are high. The inverter and the control strategy are suitable for high-efficiency and high-reliability power supply application occasions such as new energy power generation and aviation airborne power supplies.