The optical contact angle measuring instrument is an instrument for measuring the contact angle between liquid and solid materials. It adopts a dense LED cold light design, with high precision and wide range measurement capability, supporting contact angle measurement and surface tension measurement. Mainly used to characterize the wetting performance of liquids on solid material surfaces, obtaining images of droplets through optical imaging, using computer software to fit the contour of droplet images through mathematical models and obtain contact angles or surface tension, and performing surface energy calculation and wetting analysis.