<p>Mental health literacy plays a pivotal role in subjective well-being. However, this has rarely been examined among Chinese secondary vocational school students using a person-oriented method. To address this gap, the present study explores subtypes of mental health literacy and reveal their association with subjective well-being (life satisfaction, positive affect and negative affect). The Universal Mental Health Literacy Scale for Adolescents, the Satisfaction with Life Scale and the Positive and Negative Affect Schedule were administrated to 925 adolescents recruited from four Chinese secondary vocational schools. The subtypes were examined using latent class analysis, and the relationship between subjective well-being and latent class membership was analyzed using multivariate analysis of variance. The three groups and their probabilities were identified: “high mental health literacy” group, “high knowledge-low attitude” group and “low knowledge-low attitude” group. In the dimensions of subjective well-being (life satisfaction, positive affect and negative affect), “high mental health literacy” group performed better among three groups, and both “low knowledge-low attitude” group and “high knowledge-low attitude” group displayed comparable and lowest levels of life satisfaction and positive affect, as well as the highest level of negative affect. These findings revealed the population heterogeneity of mental health literacy in secondary vocational school students, and provided significant implications for future research and the development of interventions.</p>