Objective: To investigate the effectiveness of horticultural therapy on improving university students mental health problems and to provide evidence to support the application of horticultural therapy in the prevention and treatment of university students mental health. Methods: From March to May 2022,a before-and after paired design was used with a blank control group, mental health screening abnormalities were recruited from a comprehensive university in Hebei Province, including 57 in the intervention group and 21 in the control group, and the Symptom Checklist-90(SCL-90) score and hair cortisol were included as outcome indicators, which was measured by enzyme linked immunoassay Elisa double antibody sandwich method. Results: The total SCL-90 scores of the intervention group decreased ( t=4.28, P <0.01) and were significantly lower compared with the control group( t=-2.66, P <0.01), while no significant difference was observed in the control group( t=0.29, P >0.05), and the difference between the pre and post measures on each dimension of the SCL-90 was significantly lower in the intervention group (all P <0.01); the difference between the pre and post measures of hair cortisol contentration in the intervention group was statistically significant( Z= -2.75, P <0.05), and the hair cortiso contentration in pre measure group was lower than that of control group( Z=-3.48, P < 0.01 ). In contrast, the difference between pre and post measurements of hair cortisol in the control group was not significant( Z= -0.75 , P >0.05). Conclusion Horticultural therapy can improve the psychological symptoms of university students is suitable for psychological interventions in the university population and is beneficial to the health and well being of university students.