The invention provides a processing improving method for an inner hole of a thin-walled part of a pump valve body. In processing, an auxiliary vibration force absorbing cloth strip is additionally arranged on the excircle at an X section of a roughly turned blank. The improving method comprises the following steps: S1, material preparing and sawing; S2, rough turning; S3, primary finish turning; S4, secondary finish turning; S5, drilling and milling; S6, burr removing; S7, inspecting; and S8, packing and storing. The cloth strip is wound on the outer wall of a workpiece, the vibration force generated in workpiece processing can be weakened, the flutter of the workpiece is reduced, the inner hole size and the surface quality of the workpiece are ensured, the processing requirement is met, and the processing precision of the workpiece is improved, so that problems and defects in the prior art can be effectively solved.