Objective: To investigate the mental health status and related factors among primary and secondary school students in western Yunnan Province, so ao to provide scientific evidences for advancing mental health education. Methods: In June 2024, a stratified cluster sampling method was employed to select 4 584 students from 18 schools across Diqing Tibetan Autonomous Prefecture, Lincang City and Baoshan City three regions in western Yunnan Province. The Mental Health Test (MHT) was used for assessment. Latent class analysis (LCA) and Logistic regression were applied for data classification and related factor analysis respectively. Results: The overall positive detection rate of MHT was 11.81%, with a mean total score of 40.50±19.25. The predominant issues were learning anxiety (58.4%), hypersensitivity tendency (31.1%), and self blame tendency (23.1%). LCA categorized students into four groups:severe psychological problems group (74.4% detection rate), learning anxiety hypersensitivity group ( 16.4 %), learning anxiety physical symptoms group (9.2%), and healthy group (0). Logistic regression revealed that compared with the healthy group, the severe problems group showed higher risks among females ( OR =3.01), junior/senior high school students ( OR =1.88/4.02), and those with authoritarian parenting ( OR =3.54); the anxiety hypersensitivity group had higher risks for females ( OR =1.87), senior high students ( OR =1.54), boarders ( OR =1.31), and authoritarian parenting recipients ( OR = 1.85 ); the anxiety physical symptoms group demonstrated increased risks among females ( OR =2.22), senior high students ( OR =2.58), and authoritarian parenting recipients ( OR =2.74), while lower risks were observed for students with parent/grandparent guardians ( OR =0.38) and non only children ( OR =0.58) (all P <0.05). Conclusions Mental health problems are prominent among students in western Yunnan, with gender, grade level, boarding status, guardian type, and parenting style being key determinants. Recommendations include strengthening mental health education, prioritizing left behind children s psychological well being and promoting healthy development.