A fiber Bragg grating (FBG) strain tube, which is fabricated by affixing bare fiber grating to a strain tube, is designed to solve existing problems in deep displacement monitoring of pipeline landslide. Strain measurement principle of fiber Bragg grating and deep displacement calculation method of landslide measured by FBG strain tube are presented. According to results of performance test, strain sensitive coefficient of a FBG strain tube is 0.58 pm/10-6. According to field trials, measurement results of FBG strain tube are mostly agreeable with these of declinometer.