Objective: To understand the parenting styles of junior high school students in Beijing, to explore the relationship between parenting styles with students academic performance and the role of mental health in this association. Methods: From October 2019 to January 2020, a stratified random cluster sampling method was used to select 5 196 students in the first and second grades of 11 public junior high schools in urban and rural areas in Beijing, and Slort Egna Minnenar Barndoms Uppfostran-China,Middle School Students Mental Health Scale-60 and self designed questions were used in the questionnaire survey. Results: The average score of parenting style rejection dimension was (9.44±3.88), and the average score of emotional warmth dimension was (19.85±5.66). The average score of comprehensive score of students mental health was ( 1.92 ±0.73). Mental health score of girls was higher than boys (1.97±0.74)(1.87±0.71), and the differences were of statistical significance( t=5.06, P <0.01). Parental rejection and emotionally warm parenting styles were significantly correlated with students academic performance （ β =-0.54，1.15， P <0.01). Mental health played a negative moderating role between parenting style and students academic performance. The better students mental health were, the greater the influence of parenting style on academic performance. Conclusion Parenting style is related to children s academic performance. Parents should give their children more affirmation, encouragement and praise, in order to improve their academic performance.