The invention discloses an installation structure for an optical fiber temperature sensor of a transformer, and belongs to the technical field of transformer monitoring. The structure comprises an iron core, a clamping piece, a winding and spacing support bars, and further comprises the optical fiber temperature sensor and a sheath. The winding is arranged at the outer side of the iron core and comprises a low-voltage winding at the inner side and a high-voltage winding at the outer side, and the spacing support bars are arranged between the low-voltage winding and the high-voltage winding. Agroove for embedding the optical fiber temperature sensor is formed in one large side surface of one of the spacing support bars; a wire outlet of the groove is connected with the sheath, and the sheath is fixedly connected in a groove of the clamping piece; and a transmission optical fiber of the optical fiber temperature sensor is connected into a junction box outside the transformer box body through the groove and the sheath in sequence. The installation structure is convenient to install, is higher in safety coefficient of equipment, and avoids the damage of the optical fiber temperature sensor in the transformer assembling process.