Abstract: Physical exercise is regarded as an effective way to alleviate psychosocial stress, however, some studies also suggest that physical exercise cannot alleviate but exacerbate psychosocial stress. This study aimed to clarify the effects and mechanisms of physical exercise on psychosocial stress, so as to provide scientific and reasonable physical exercise programs for stress alleviation.The results indicated that the cross stress adaptation hypothesis and the antagonistic stress hypothesis explained partly relationship between physical exercise and psychosocial stress. There were dual mechanism systems of physical exercise in affecting psychosocial stress, i. e., the HPA system can promote habitual adaptation of the stress response system, and the neuro-immune,emotion, physical fitness and MGBA system can increase the positive states of the stress response system. Based on the dual mechanism systems, the following physical exercise programs were suggested: Yoga, Tai Chi, Qi Gong, outdoor walking and leisure sports are recommended to relieve greater psychosocial stress; long-term regular high intensity and high amount exercise including endurance, resistance and HIIT were recommended to increase the adaptation of psychosocial stress.