Internet addiction is a new psychological disorder that has emerged with the creation of the Internet. Internet addiction is manifested by addiction to the Internet, resulting in a significant decline in physical and mental functions. Most Internet addicts are teenagers, who are in the critical period of physical growth, character development and learning life. Internet addiction makes these teenagers’ physical, learning and psychological health suffer serious damage, and may even lead to sudden death, suicide, robbery, injury, murder and other serious incidents. The formation of Internet addiction is related to the attractiveness of the Internet itself, but it is also related to the addict’s own personality characteristics and psychological factors. The treatment of Internet addiction requires a combination of treatment modalities, with psychotherapy being the main one. Some medication can also be added if necessary.