In this paper,a dual physical quantity sensing unit of micro force and micro displacement based on fiber Bragg grating (FBG) is designed.A rectangular cantilever beam type elastic body structure and two FBG patch methods are adopted,which can improve the force and displacement sensitivity and realize temperature compensation.The displacement sensitivity can be adjusted by changing the fixed position and length of the cantilever beam.The performance of the sensing unit is theoretically analyzed and experimentally verified.The results show that the force test sensitivity is 889 pm/N in the 0～1.2 N measurement range,the theoretical and experimental average relative error is 6.6%,and the force resolution is 1.1 mN.The displacement sensitivity decreases with the increase of the cantilever beam length L.The displacement sensitivity is 60.7 pm/mm and 200.3 pm/mm respectively,when L is 149mm and 99mm.The displacement resolution is 5μmand the linearity of the sensing unit is above 0.999,which maintains an excellent linearity and can meet the application of micro force and micro displacement of different ranges.