The utility model relates to a station service power wiring system applied to a two-drive-one gas-turbine electric power plant. The station service power wiring system is formed by arranging a gas-turbine generator wiring system and a steam-turbine generator wiring system which are respectively connected with an in-plant booster station, wherein a high-voltage first bus and a high-voltage second bus are arranged inside the gas-turbine generator wiring system and are respectively connected with house loads of the gas-turbine generator wiring system and the steam-turbine generator wiring system, and the high-voltage second bus is further connected with a black-start diesel engine. Therefore, the station service power wiring system can be powered by three reliable power sources, and can be driven to operate via the power generated by the black-start diesel engine in the state that the whole plant is power off, the reliability of the high-voltage buses is improved, the influence of any power source failure on the safety operation of the electric power plant is reduced, and the failure range is narrowed; and since the steam-turbine generator set is not provided with a plant-used high-voltage transformer with no house load, the quantity of plant-used high-voltage transformers is reduced, the investment is saved, and the operating loss is reduced.