The high-pressure synthesis of lithium-ion battery ternary precursors and lithium iron phosphate precursors involves high temperature and pressure, weak acid and alkali corrosion, and high-precision purity requirements for materials. Ordinary 316L stainless steel reactors are prone to intergranular corrosion and powder shedding from the inner wall, contaminating battery raw materials. Our factory, specifically addressing the needs of the lithium battery industry, uses 316Lmod ultra-pure stainless steel to manufacture high-pressure synthesis reactors, optimizing the lining polishing and intergranular corrosion control processes. The material undergoes ultra-low carbon refining treatment, significantly reducing carbon content and preventing carbide precipitation during welding and high-temperature conditions, thus eliminating intergranular corrosion defects. The inner wall of the reactor employs a multi-stage mirror polishing process, resulting in a high degree of smoothness and eliminating micropores, preventing material residue and metal dust shedding, and ensuring the purity of precursor materials. Inert gas shielded welding is used throughout the welding process, followed by solution treatment to uniformly dissipate welding stress and intergranular defects. The equipment is suitable for continuous lithium-ion battery precursor synthesis operations, with no corrosion, no powder shedding, and no material contamination, meeting the high-precision production standards of lithium-ion new energy.