The machine adopts portable design. It can be directly placed on the surface of the sample to test the contact angle formed by the droplets on its surface, and then test the cleanliness, adhesion and treatment effect of the surface. It is widely used in nondestructive and mobile detection of large samples (such as glass, LCD screen), special-shaped samples (such as car body, bathtub), special working environment (such as outdoor environment, production line) and other fields.