An indoor voltage transfer comprises an insulating shell, a primary side and a secondary side. The primary side comprises a first wiring terminal, a second wiring terminal and a primary coil. The first wiring terminal is connected with one end of the first shielding layer of a first winding which winds the primary coil through a wire. The other end of the first shielding layer is connected with the first winding of the primary coil. The first winding winds a framework. One side of the second wiring terminal is of a symmetrical structure. The windings at two ends of the second wiring terminal are connected through a connecting section winding. The second coil of the secondary side sleeves an annular iron core. A third shielding layer winds the annular iron core. The secondary coil is correspondingly connected with the secondary wiring terminal. The primary coil sleeves the secondary coil. The two shielding layers of the primary side are high-voltage shielding layers. The third shielding layer is a low-voltage shielding layer. The transformer is high in load capacity, high in capacitivity, low in partial discharge magnitude, stable and reliable in performance and simple in structure.