To solve the problems such as low monitoring efficiency and limited number of measuring points in the current internal displacement monitoring

a monitoring method by connecting in series on a transmission fiber to form deformation sensing array is proposed and a novel inclination measuring instrument based on fiber Bragg grating（ FBG） is researched. Laboratory tests are carried out to analyze on performance and the accuracy of the inclinometer under different deformation conditions. The calibration experiment shows that the inclinometer has good linearity

its angular resolution is 0. 015°. The simulation test result indicates that the measurement of inclinometer is in good agreement with the actual deformation.