The invention provides an automatic-control temperature adjusting device of an optical fiber fusion splicer. The device is used for solving the problem that the optical fiber fusion splicer is influenced by temperature and cannot work normally. The device comprises a rack, a heat-dissipation device, a heating device, a thermal energy circulating system and a control system. The heat-dissipation device, the heating device, the thermal energy circulation system and the control system are all installed on the rack. The thermal energy circulation system comprises a heat conducting oil pump, a first circulating tube, a second circulating tube, a heat-exchanger tube, an oil outlet pipe, an oil return tube, an oil tank and a water tank. The heating device is arranged on the bottom of the water tank. The control system comprises a single-chip microcomputer and a temperature sensor. The temperature sensor is fixed at the outer side of a heating part of the optical fiber fusion splicer. According to the invention, an intelligent control and conditioning mode is used, the optical fiber fusion splicer is enabled to dissipate heat automatically under the influence of a high temperature and perform heating automatically under the influence of a low temperature, and the technical problem that the optical fiber fusion splicer is influenced by temperature and cannot work normally can be solved effectively.