Abstract: The repeatability of structural strain measurement data at high temperature (HT) is the premise and basis for judging the validity of measurement results. In this paper, the quartz lamp radiation heating technology was used to construct the transient radiation heating environment and the thin-walled flat alloy material structure was taken as the measurement object. The repeatability of strain measurement data obtained by optical fiber strain sensor in the transient heating environment was experimentally studied, so as to verify its applicability to the transient HT strain measurement of alloy materials. The test results show that the deviation between the optical fiber sensor and the K-type thermocouple is less than 1.76%. When mounting surface heated, the maximum transient temperature rising rate reaches 18 ℃/s, the maximum structural temperature reaches 850 ℃, and the maximum strain of the structural part is 9 848.2 με under this temperature. The repeatability of the three experimental measurements is better than 1.42%. When non-mounting surface heated, the difference in the mean of the measured data under the same temperature is only 0.67%. In conclusion, the optical fiber strain sensor is suitable for the strain measurement of alloy structure in the transient radiation heating environment by quartz lamp.