The function of LED optical lens is to encapsulate the LED chip into LED photoelectric device. Optical design must be carried out. One optical design mainly determines the luminous angle, intensity, intensity distribution, color temperature range and color temperature distribution of light-emitting devices. An optical designer ensures the quality of the light out of each LED luminescent device. In a sense, only one optical design is reasonable, can the design of the two LED optical lens be successfully implemented, thus improving the effect of lighting and display. The three major factors of optical design are chip, bracket and mold grain. The LED chip is the main body of the luminescence, and how much light is directly related to the quality of the chip. The bracket carries the chip and acts as a fixed chip. The matching between the shape and size of the support bowl and the chip plays an important role in the light output efficiency. After mold filling with epoxy resin, it becomes a lens. The angle of the light and the quality of the spot are all related to the LED optical lens formed by the mold.