分析了蓝宝石光纤温度传感器测试系统组成及工作原理，由于黑体腔膜层内外表面存在较大温差，使得该系统测出的被测物温度存在一定误差.为了解决这一问题，运用分离变量法从黑体腔内表面温度外推出黑体腔外表面温度，降低了测试对传感器的性能要求，实验验证了该方法的可行性，提高了蓝宝石光纤黑体腔温度传感器的测温精度.

The composition and the working principle of the test system for the sapphire optical fiber temperature sensor were analyzed. As there is a big temperature difference between the inner and outside surface of black body cavity, so the error of temperature of the measured object is presented. To solve this problem, a process of separating variables was used to derive the outer surface temperature of black body cavity from the inner surface temperature of the blackbody cavity, which further improved the performance of the sensor required by test. The experiment tested the feasibility of this method, and the measurement accuracy of the sapphire optical fiber blackbody cavity temperature sensor was improved.