The invention discloses a high-voltage frequency converter adopting ultra-high voltage direct input. The high-voltage frequency converter adopting the ultra-high voltage direct input comprises a pre-charging system, a phase shifting transformer, a power system and a control system; the current is directly input into the high-voltage frequency converter on the input side of a high-voltage bus; thesecondary side of the phase shifting transformer remains unchanged from the original design; the pre-charging system uses a 110kV circuit breaker and a current limiting resistor; the control system and power system of the high-voltage inverter remain unchanged; the changed engineering amount in the design is small, and the stability of the traditional high-voltage frequency inverter design is inherited. According to the invention, the current is directly input into the high-voltage frequency converter on the 110kV high-voltage bus, and the configurations such as the phase shifting transformerand pre-charging cabinet in the system are correspondingly changed; therefore, the efficiency loss of the intermediate transformer is reduced by 1-3%, the efficiency of the entire distribution systemis increased, the stability of the inverter system is improved, and the probability of failure is reduced; meanwhile, the high-voltage frequency inverting inverter unit body pre-charging mode is used.