A method for generating an all-fiber cylindrical vector beam (CVB) by using a fiber Bragg grating (FBG) inscribed in ring core fiber (RCF) is proposed. The FBGs are inscribed using femtosecond laser phase mask scanning technique, chosen for its large ring core diameter and low photosensitivity of RCF. Additionally, a lateral offset splicing spot is introduced to couple the fundamental mode to the second order modes. Switchable LP01 and LP11 mode lasers can be achieved, meanwhile, azimuthally and radially polarized CVBs are successfully realized by adjusting the polarization controllers.