The invention relates to the field of 
machining, in particular to a method for 
machining a thin-wall bearing housing part. The method comprises the following steps that a blank is forged, and a process construction chuck is reserved; rough turning is carried out, wherein the appearance of a workpiece is roughly turned on a common lathe, a ladder hole of the workpiece is roughly turned, stabilizing treatment is carried out, and the 
internal stress of the workpiece is eliminated; finish turning is carried out, finish turning is carried out on the workpiece on a numerically controlled lathe, the working allowance of 0.9 mm is reserved on the single side of the outer circle and the single side of an inner hole; rough 
grinding is carried out, wherein the two end faces of the workpiece are ground on a 
surface grinding machine, and the depth of parallelism between the two end faces is kept within 0.05 mm; rough 
grinding is carried out, wherein the construction chuck end face of the workpiece is sucked by a suction cup on a universal 
grinding machine, alignment is carried out according to the outer circle, and the outer circle, the inner hole and the end faces of the workpiece are ground roughly. The 
machining process is simple, the scheme is simple and practical, clamp design is reasonable, application is convenient, manufacturing cost is low, the part is easy to dismount, the use effect is good, the machining quality of the workpiece can be ensured, workpiece efficiency can be improved, and the method is suitable for 
batch production of the large-
diameter thin-wall part.