As a behavioral addiction, Internet addiction has become a global problem that seriously affects people’s mental health. According to the neurobiological model of brain development, revealing the neural mechanisms of reward and the cognitive control system of Internet addicts is the key to solving internet addiction. The key to the problem of addiction is also a major issue in psychological research. Behavioral research has explored the characteristics of high reward seeking and low cognitive control in Internet addiction; research on neural mechanisms has revealed that the deficits in reward and cognitive control systems are the root of this behavior. Comparative studies with drug addiction have found that Internet addiction has a unique reward mechanism. These studies have deepened the understanding of the psychological and neural mechanisms of Internet addiction, but there are still differences in the screening and inclusion criteria for Internet addiction. There are some problems that need to be solved urgently, such as science, general classification, lack of causal research, controversial intervention and treatment effects, and loopholes in research paradigms.