There are many problems of using weighing and cutting method for optical glass based on artificial experience, such as large errors, low efficiency and poor security. In order to solve the above problems, an automatic weighing and cutting equipment for strip optical glass is built based on machine vision, and an automatic weighing algorithm is designed for the equipment combined with structured light. The position feature of the glass cross section is identified after the optical glass image is collected by the high speed industrial camera. The cross sectional area is calculated by using the location information. Then the area is integrated with the help of the glass propulsion feed of the servo motor. And the cumulative volume and the mass size are calculated. When the cutting conditions are satisfied, the glass will be cut. Experimental results and practical application in the factory show that, the system has the characteristics of high precision, high efficiency and high safety, and the actual cutting error is less than 0.3 g. Therefore, The automatic weighing and cutting method can cut the strip optical glass efficiently and accurately.