The invention discloses a (3N+3) switched cascaded based multi-port energy-feedback high-voltage converter and a control method thereof. The multi-port energy-feedback high-voltage converter is formedby cascading a plurality of (3N+3) switch units, each (3N+3) switch unit comprises a three-phase bridge-type pulse width modulation (PWM) rectifier, a DC-side capacitor and a (3N+3) switch converter,N three-phase output ports are formed in the (3N+3) switch converter and are sequentially recorded as a port 1, a port 2 until a port N, the multi-port energy-feedback high-voltage converter is formed by cascading the plurality of (3N+3) switch units, the port 1 of the (3N+3) switch converter in each (3N+3) switch unit employs an inductance cascading mode, and the other ports of the (3N+3) switchconverter in each (3N+3) switch unit employ a three-phase transformer cascading mode. By the multi-port energy-feedback high-voltage converter, a plurality of load ports can be provided, regenerationenergy among a multi-port load can be directly utilized, the energy utilization efficiency is improved, the feedback power grid pressure is reduced, and meanwhile, the equipment volume also can be reduced.