交叉敏感问题是光纤光栅传感器在实际应用中需面对的一个关键问题。从光纤Bragg光栅的传感理论出发，分析了光纤光栅在同时测量应变和温度时引起交叉敏感的物理机理，建立了带有温度-应变交叉灵敏度系数的光纤Bragg光栅反射波长方程。利用双波长矩阵算法针对上述建立的光纤光栅方程进行了误差分析，获取了在交叉敏感情况下温度和应变的相对误差曲线图。结合相对误差表达式和曲线图分析讨论了交叉敏感对测量带来的影响。结果表明在温度和应力测量中随着测量温度或者应变变化量的增大，忽略交叉敏感项而带来的测量误差越来越明显。

The cross-sensitivity is a key problem in the application of fiber grating sensors. Based on the sensing theory of fiber Bragg gratings (FBG), the physical mechanism of the cross sensitivity in simultaneous strain and temperature measurement with fiber grating is analyzed. The FBG reflected wavelength equation with the temperature-strain cross-sensitivity coefficient is established. The error analysis of the equation was made with the dual-wavelength matrix algorithm and the relative error curves of temperature and strain were obtained in the case of cross-sensitivity. The effects of the cross-sensitivity on the measurement were discussed and analyzed according to the expressions and curve diagram of the relative error. The result shows that the relative errors of temperature or strain grow significantly with the increase of temperature or strain variance during the measurement of temperature and stress, and the crosssensitivity is not negligible when the relative errors are great enough.