The aluminum extrusion container liner is a critical wear component that directly impacts profile quality, production efficiency, and tooling costs for aluminum profile manufacturers. This article provides a professional technical overview of container liner engineering, covering material selection (H13 hot-work tool steel), advanced surface treatments (nitriding, PVD coatings), and the precision manufacturing process — including forging, vacuum heat treatment, honing, and shrink fit assembly. It compares two-piece and three-piece container designs, discusses thermal management for isothermal extrusion, and details best practices for preventive maintenance, condition monitoring, and liner refurbishment via grinding, re-nitriding, or laser cladding. Performance metrics, industry standards, and emerging technologies such as digital twins and IoT-enabled smart monitoring are also addressed. The article concludes with a practical selection guide to help extruders evaluate total cost of own