The invention belongs to the technical field of high voltage electric power equipment, and particularly relates to a distributed optical fiber temperature measurement system and method used for a dry type reactor. The system comprises the dry type reactor and also comprises temperature-sensitive optical fibers, transmission optical cables, an optical fiber temperature measurement instrument, a monitoring host and a sound-light alerter. The temperature-sensitive optical fibers are arranged in the air channels of the dry type reactor. The temperature-sensitive optical fibers with great insulating property are utilized to act as sensors to be arranged in the air channels of the dry type reactor for monitoring the problems of the reactor, and a strategy is provided so that early warning and alarm signals are provided when temperature values are abnormal, and a situation that faults further develop into accidents can be prevented. The system has the characteristics of simple structure and convenient operation so that working safety can be significantly enhanced.