An extra-large precursor tank for centralised feeding systems in semiconductor industrial parks. A composite polishing process on the inner wall greatly reduces media adsorption and residue, preserving high source material purity. The outer wall is sandblasted and coated with two anti-corrosion layers, suited to long-term outdoor storage at the plant, and an integrated load-bearing base allows forklift transfer of the whole unit. The tank has a high pressure safety threshold with a temperature range matching ambient plant storage. Its large capacity reduces refilling frequency, enabling unified, pressure-stable and sealed feeding across multiple thin-film lines while lowering the risk of oxidation contamination.