Because of the prevalence of chronic disease, it is a major challenge in the world to effectively change bad health habits. So the article explored why habit was primary form of behavior patterns, explained how health habits were formed, then analysed the different role of rationality, consciousness and unconsciousness in changing behavior and habits, advanced how to change health habits effectively. Finally, according to the mechanism of the formation and transformation of habits, the author provided relevant recommendations and measures to effectively control the spread of chronic diseases in practice.