As the city expanding, commuting time is getting longer. According to the "2018 China Urban Commuting Research Report", the commuting time in major cities such as Beijing and Shanghai have exceeded one hour. As a limited resource, the shortage of time inevitably makes people feel pressure, which adversely affect the psychosocial adaptation. The effect of commuting time on mental health has become a growing focus for researchers. However, the underlying mechanism has not been studied systematically. In recent years, the Party and the government have paid more and more attention to the better life of people. Better life is closely related to people's mental health. The current assessment of better life is, on the one hand, better life experience of the current living conditions, and on the other hand, the needs for better life in people's ideals. As a daily activity that connects family and work, Changes in commuting time are often accompanied by changes in leisure time, which are closely related to the better life experience and needs of the people. Therefore, this study intended to explore the internal effect of commuting time on mental health from the perspective of better life. This study not only helped to understand the better life of people, but also provided a reference for the government to formulate plans and policies to safeguard the physical and mental health of the people. The purpose of this study was to explore the influence mechanism of commuting time on mental health. Totally 4,199 people (2923men, mean age=30.24 years, SD=7.40) were surveyed using the questionnaire survey APP “Survey Baby”. Participants anonymously completed Commuting Time Scale, Depression, Anxiety and Stress Scales(DASS-21; 21items,three factors: Depression, Anxiety and Stress; α=.96), Better Life Experience Scale(BLES; 28items, three factors: National society, Personal material and Family relations; α=.96) and Better Life Needs Scale(BLNS; 28items, three factors: National society, Personal material and Family relations; α=.98). All the measures showed good reliability and validity in the present study. The results indicated that: (1) Commuting time, mental health, better life experience and better life needs were significantly correlated with each other; (2) Better life experience played a mediating role between commuting time and mental health; (3) Better life needs could not only significantly moderate the relationship between commuting time and better life experience, but also significantly moderate the relationship between better life experience and mental health. These findings revealed the relationship between commuting time and mental health from the perspective of better life. In addition, the research findings could provide some available suggestions for improving people's better life experience and mental health. Firstly, it is beneficial to reduce commuting time. The government and transportation departments should take effective measures to solve the traffic problems. Secondly, it is important to help people improve the level of better life needs. The hope of better life in the future will provide individuals with strong motivation to adopt more healthy behaviors to maintain their physical and mental health.