Objective: To understand the relationship between residential neighborhood green space and mental health of middle school students, so as to provide a theoretical basis for mental health promotion among of middle school students at the level of residential environment. Methods: From October to December 2023, 1 258 students from three junior high schools and two general high schools in Panlong, Wuhua, Chenggong, and Guandu districts of Kunming City were selected by stratified cluster random sampling method. Conducting onsite questionnaire survey using the Mental Health Inventroy of Middle School students, residential neighborhood green space were evaluated using normalized difference vegetation index (NDVI). Analysis of variance, Pearson correlation analysis and linear regression analysis were used to analyze the relationship between as green space in residential neighborhoods and the mental health of middle school students. Results: The average mental health score of middle school students in Kunming was (2.02± 0.69 ), of which 447 (37.92%) had mild mental health problems, 107 (8.51%) had moderate mental health problems, and 12 ( 0.95% ) had more severe mental health problems. Mental health scores of middle school students varied significantly by gender, grade, and family income ( t/F =6.99, 7.15, 3.70, P <0.05). Correlation analysis showed that NDVI_250 m, NDVI_500 m, and NDVI_1 000 m were all negatively correlated with the total mental health scores of middle school students ( r =-0.07,-0.09, -0.10 , P <0.05). Multiple linear regression analysis showed that gender, grade, NDVI_250 m, NDVI_500 m, and NDVI_1 000 m were infuencing factors on the mental health of middle school students( B =0.25，0.05，-0.47，-0.67，-0.78, P <0.05). Conclusions Mental health of middle school students in Kunming is related to green space in different buffer zones around residences. The mental health education of middle school students should be strengthened, especially for girls and senior students, optimizing resources to reduce pressure, and improving the quality of green space in residential communities to improve the mental health of adolescents.