The coupling of the sensing cable to the surrounding soil is essential to the application of distributed optical fiber monitoring technology for monitoring soil deformation, particularly the coordination of fiber-soil deformation under low confining pressures, which seriously affects the accuracy of the measurement data. In this study, the anchored fiber-optic cable is designed and the fiber-soil pull-out test is performed to investigate the effects of backfill material and anchoring method on fiber-soil coupling under low confining pressures. Results show that the backfill material considerably affects the fiber-soil coupling. The higher the clay content is, the better the coupling is. Under low confining pressures, the fiber-soil coupling can be effectively enhanced by adding the wafer anchor into the sensing cable. Decreasing anchor interval and increasing anchor diameter can improve the fiber-soil coupling.