降低光纤布拉格光栅(FBG)应变传感器的应变灵敏度是解决传感器量程小、无法监测大应变问题的一种重要方法。为了监测构件在使用过程中的应力应变变化，提出了螺旋倾斜式光栅复合技术，建立了光栅实测应变与试样实际应变间的理论关系,在不同螺旋倾角下进行了光栅应变灵敏度的测量试验。试验结果表明，该方法能有效降低光栅应变灵敏度，增大光栅应变测量量程。

Reducing the strain sensitivity of fiber Bragg grating (FBG) strain sensor is one important method to solve issues of small measurement range and undetectable large strain. In order to monitor stress and strain changes of components during use, one composite technology of spiral and slant gratings is proposed. The theoretical relationship between the measured strain by FBG and the actual strain of specimen is established. The measurement experiment of the grating strain sensitivity under different spiral-slant angles is done. The experimental results show that the proposed method can effectively reduce the strain sensitivity of FBG and increase the strain measurement range of FBG.