In the ink components, fatty acids are usually used as lubricants. The lubricants are also cosolvents. The functions of the lubricants include: A, lubricate the balls and provide fluent writing; B, prevent the ink from drying, so that the ballpoint pen has a stable and good initial Pen performance; C. Increase the depth of dye dissolution and improve the color of the dye. The introduction of fatty acids is corrosive to some nib metals (such as copper alloys), causing a non-homogeneous crystalline substance in the ink to block the passage, thus shortening the service life of the ballpoint pen. The method of using fatty acid and supplemented by corrosion inhibitor can solve the corrosion problem and meet the lubrication requirements. The corrosion inhibitor used in the experiment is dissolved in fatty acid in a saturated state, which can achieve the purpose of corrosion protection.