The invention discloses an aluminum cylinder part machining method. The aluminum cylinder part machining method specifically comprises the following steps: blanking or forming an aluminum cylinder part blank, roughly machining the outer diameter of the aluminum cylinder part blank and the overall length of a workpiece, roughly turning an inner hole of an aluminum cylinder part, performing stability treatment, finely turning an appearance, finely turning the inner hole, and performing final inspection. The aluminum cylinder part machining method ensures the machining precision of a precise thin-walled aluminum cylinder part; the precise thin-walled aluminum cylinder part is positioned and clamped by adopting various clamps in different machining stages; and the problem about deformation ofthe precise thin-walled aluminum cylinder part under the action of clamping force in product production is solved. An aluminum cylinder part with the wall thickness of 3 to 6 mm can be machined; the dimensional tolerance is within 0.05 mm; the shape and position tolerance can also be ensured within 0.05 mm; the aluminum cylinder part machining method is applicable to machining various precise thin-walled aluminum cylinder parts; the positioning precision is high; the operation is simple; the workpiece is convenient to load and unload; the clamping force can act on a clamped workpiece uniformly; and the clamping force can be adjusted according to different situations.