In view of the problems such as less automation,low measurement accuracy,not e asy use in the large area and lack of reliable online monitoring in the traditional landslide monitoring techn ologies,this paper uses fiber Bragg grating (FBG) bending sensing technology,and researches its structural principle s and specific applications in measurement of slope surface deformation and deep displacement.On the basis of analyzing the FBG bending sensing principle using simple supported beam and cantilever beam tuning structu re,FBG series with different center wavelengths are selected and pasted on the PVC pi pe.The principle feasib ility using simple supported beam and cantilever beam tuning FBG bending sensing to test the slope surface de formation and deep displacement has been verified.Experimental results show that the FBG waveleng th changes have a clear linear relationship with its pasting locations on PVC pipe.And the maximum FBG strain s ensitivities are 0.245nm/mm and 0.166nm/mm respectively for the two beam tuning structures.In addition,using th e method of pasting FBG on PVC pipe with symmetric 180° position,the FBG detection sensitivity can be improved .Meanwhile,the influence of temperature changes on FBG bending sensor can be eliminated.