The utility model relates to a complete indoor high -voltage substation technical field, be to current main become under the room design of oil storage hole unreasonable cause retrieve inconvenient, the cost is high, not pleasing to the eye etc. And the complete indoor transformer station owner becomes oil discharge system that provides. Including the half layer of shear force wall on the cable and the structural slab that support main transformer, main transformer installs on structural slab upper portion, and reserve on the structural slab of main transformer below or processing has the mounting hole of going up, still including arranging oil pipe, arranges during oil pipe one end locates the mounting hole, is equipped with in row oil pipe upper end and prevents the filter screen of cobble in getting into row oil pipe, and row oil pipe one end runs through and extends to the oil extraction shaft bottom behind the shear force wall. The utility model discloses for all main room below oil storage holes that become of traditional structure cancellation, the row of setting oil pipe, row oil pipe run through structural floor slab and shear force wall department sets up the stagnant water steel sheet, arranges oil pipe upper portion and sets up the reinforcing bar net littleer than cobble diameter, prevents that the cobble from entering into row oil pipe.