A flexible DC converter station rapid switching standby phase transformer arrangement structure mainly comprises a high-voltage tubular bus, a medium-voltage tubular bus, a three-phase neutral point tubular bus, a standby phase neutral point tubular bus, a transformer high-voltage side sleeve, a medium-voltage side sleeve, a low-voltage side sleeve and a neutral point sleeve. The high-voltage tubular bus, the medium-voltage tubular bus, the three-phase neutral point tubular bus and the standby phase neutral point tubular bus are single phases for switching a fault phase and a standby phase; the method comprises the following steps: a) removing all leads of a fault phase transformer, and withdrawing a fault phase; b) directly connecting a fault phase high-voltage incoming line to a standbyphase transformer through a high-voltage bus, and connecting a standby phase medium-voltage side to a medium-voltage side outgoing line corresponding to the original fault through another bus; c) thelow-voltage side of the standby phase is connected to a nearby low-voltage side outgoing line through a low-voltage bus, and d) fault phase quitting and standby phase switching are completed at the same time, and normal work is recovered after power-on, so that the working hours are greatly shortened, and economic benefits are improved.