The embodiments of the invention provide an all-fiber one-order OAM (orbital angular momentum) mode generation system. The all-fiber one-order OAM mode generation system comprises a mode filtering unit, a mode disturbing unit and a mode generating unit, wherein all of the mode filtering unit, the mode disturbing unit and the mode generating unit belong to fiber type units; the mode filtering unit is used for filtering away high-order modes in fibers to obtain low-order linear mode LP01 modes, wherein the input of the mode filtering unit is obtained after light rays pass through a polarization controller; the mode disturbing unit is used for receiving the LP01 modes output by the mode filtering unit and converting the LP01 modes into LP11 modes; the mode generating unit is used for receiving the LP11 modes output by the mode disturbing unit and generating one-order OAM modes. According to the all-fiber one-order OAM mode generation system, the insertion loss of the one-order OAM mode generation system can be reduced.