The invention relates to a fixture with the adjustable axial accuracy, and a method for parts processing by utilizing the fixture. The fixture not only is simple in structure and convenient to operate, but also meets the requirement on the accuracy of form and position of a workpiece to be processed. The fixture structurally mainly comprises a clamping tool and an embracing tire, wherein the clamping tool comprises a support part, a flexible part and a locking part sequentially arranged along the axial direction of the clamping tool; the support part is used for fixing the clamping tool; the flexible part produces 0 to 0.2mm-deformation along the axial direction of the flexible part under the action of the external force; and the locking part and the embracing tire are matched for clampingthe workpiece to be processed.