Environment-friendly insulating coating capable of improving surface brightness of oriented silicon steel

The invention relates to an environment-friendly insulating coating capable of improving the surface brightness of oriented silicon steel. The environment-friendly insulating coating comprises the following raw materials in percentage by weight: 24%-40% of dihydric phosphate, 0.1%-0.65% of silicate, 0.2%-4% of boric acid, 10%-29% of colloidal silicon dioxide, 0.02%-0.25% of copper-tin brightening agent and the balance of pure water. According to the environment-friendly insulating coating disclosed by the invention, as the silicate and the copper-tin brightening agent are added, after annealing at a temperature of at least 800 DEG C, the surface brightness of the oriented silicon steel can be increased from the existing level of not exceeding 15 to at least 25 under the common comprehensive action of the two, namely the silicate and the copper-tin brightening agent; the friction coefficient is small, and the color is dark and uniform; and a user can easily operate and manage the insulating coating in the process of preparing an iron core of a transformer, the operation is time-saving and labor-saving, and the efficiency is high. Thus, the market requirements can be completely met.