The utility model provides a nuclear power station 220kV power supply system, includes two generating lines, concatenates article two, female between the generating line allies oneself with switch, two 220kV circuits, one and hauls oneself willingly into the device fully, article two, the 220kV circuit corresponds the connection respectively article two, generating line and long -range two transformer substations in addition, and be provided with a line switching in every 220kV circuit, haul oneself willingly into fully the device be connected to female ally oneself with switch, line switching article two, the 220kV circuit and article two, generating line, female ally oneself with switch and line switching be in close position and another line switching be in divide the position, or two line switchings all be in and close position and female and ally oneself with a switch and be in and divide, it switches to closing the position to haul oneself willingly into the line switching of device in a 220kV circuit for the generating line power supply loses the female antithetical couplet switch of electric post -trigger or another 220kV circuit fully, so can make another 220kV circuit give two generating line power supplies simultaneously, in time recover to supply power for the generating line, consequently need not the artifical power supply recovering of participating in, the generating line that can not appear resulting in because the 220kV circuit loses the electricity loses the problem of electricity for a long time.