The invention discloses a transformer insulator, which mainly comprises a cylindrical insulated pillar. The bottom part of the insulated pillar is provided with a cylindrical mounting thread column; the top part of the insulated pillar is provided with a connection rod; the top part of the connection rod is provided with a bent tubular insulated elbow; one end of the insulated elbow is opened vertically and upwardly, and the other end of the insulated elbow is opened towards a horizontal direction; two ends of the insulated elbow are both provided with disc-shaped insulated discs; the bottom part of the insulated elbow is provided with a cylindrical supporting rod; the supporting rod is parallel with the insulated pillar; a section of spring is arranged in the middle of the supporting rod;and a flat plate-shaped mounting plate is vertically arranged on the bottom part of the supporting rod. Due to mounting of the single transformer insulator, a wire can be introduced to the transformer, the stability is good, the insulated elbow is used to coat the wire, and accidents such as short circuit or electric leakage can be effectively prevented.