The invention relates to a split three-phase solid-sealed insulated upper outlet seat component used for an outdoor ring main unit of a power system. The component is provided three rectangular seat bodies which are arranged abreast. Each seat body is provided with a bus jack is reserved along a length direction. The bottom of the jack is provided with a quincuncial contact finger. The top of each seat body is provided with a raised connecting seat. The three connecting seats are arranged in a staggering way. The center of each connecting seat is provided with a conductive pole. The middle part of the conductive pole is provided with a jack in which a watchband contact finger is arranged. A frame-shaped groove is reserved around the conductive pole on the connecting seat. The two sidewalls of the groove are inclined surfaces. A copper insert is wrapped in the seat body. One end of the copper insert is connected with a corresponding quincuncial contact finger, and the other end of the copper insert is connected with a corresponding conductive pole. The component solves the problems of low insulativity, high manufacture cost, inconvenience of maintenance and inadaptability to severeenvironments caused by the adoption of an exposed copper bar in outlet connection in the conventional ring main unit, and is particularly applied to the lower outlet of a main loop of the outdoor ring main unit with the three-phase AC of 50Hz and the rated voltage 12kV.