The invention discloses a method for manufacturing an aluminum liner of a vehicular composite cylinder, which is used for manufacturing the aluminum liner of the vehicular composite cylinder. The aluminum liner consists of a thin-walled cylinder body of the aluminum liner, an end enclosure gradually thickening part and an opening part. The aluminum liner is manufactured by adopting a method of reducing the wall thickness of a thick-wall aluminum pipe by over 60 percent by one time of rotary pressing by a 450 strong spinning reduction machine, forming the end enclosure part and the opening part by using a 412 spinning necking machine, and machining the connecting threads on the opening part after solution ageing heat treatment. The aluminum liner of the vehicular composite cylinder has the advantages of high quality, large diameter, thin wall thickness, small weight capacity ratio (weight / capacity), high geometric dimensioning accuracy, high quality of inner and outer surfaces and the like, and has the excellent application and market prospects.