Depending on its duration, stress can be divided into chronic and acute stress, both of which can be detrimental to an individual's mental health. Psychological suzhi may act as a protective factor that buffers the adverse effects of stress. This study aimed to explore the moderating role of psychological suzhi in the relationship between these two types of stress and mental health based on a dual-factor model of mental health. Study 1 explored the moderating role of psychological suzhi on the relationship between chronic stress and mental health using the Adolescent Self-Rating Life Events Check List, College Student Psychological Suzhi Scale Brief Mental Health Version, Satisfaction With Life Scale, and 12-item General Health Questionnaire to investigate 919 Chinese college students. A hierarchical regression model was used to examine the moderating effects. Study 2 examined the moderating role of psychological suzhi on the relationship between acute stress and mental health. Participants ( = 56) were classified into high ( = 30) and low ( = 26) psychological suzhi groups based on the Psychological Suzhi Scale. They completed the Trier Social Stress Test for Groups and a specific control condition, and their state anxiety and happiness levels were assessed. Data were analyzed using a mixed-design repeated-measures ANOVA. The results of Study 1 revealed that psychological suzhi moderated the influence of chronic stress on the negative indicator of mental health (psychological symptoms) (β = -0.18, t = -6.90, p < 0.001). The results of Study 2 showed that psychological suzhi moderated the effect of acute stress on the negative indicator of mental health (state anxiety) [F (1, 54) = 4.79, p < 0.05, η = 0.08]. Psychological suzhi can moderate the influence of both chronic and acute stress on the negative indicators of college students' mental health but cannot moderate the influence on the positive indicators of mental health.