Optical glass is mixed with high-purity oxides of silicon, boron, sodium, potassium, zinc, lead, magnesium, calcium, barium, etc. according to a specific formula, melted in a platinum crucible at high temperature, and stirred evenly with ultrasonic to remove air bubbles; Cool down slowly over time to avoid internal stress in the glass block. The cooled glass block must be measured by optical instruments to check whether the purity, transparency, uniformity, refractive index and dispersion rate meet the specifications. Qualified glass blocks are heated and forged to form optical lens blanks