Objective:To explore the relationship and mechanism of loneliness between stress perception and life satisfaction of postgraduates.Methods:A questionnaire survey was conducted among 728 postgraduate students enrolled in the national entrance examination,utilizing Loneliness Scale,Stress Perception Scale,and Life Satisfaction Scale.The data was analyzed using SPSS 25.0 for independent sample t-tests,analysis of variance,Pearson correlation analysis,and multiple regression analysis.Structural equation modeling was performed using AMOS26.0 software to construct and evaluate the data.Results:(1)There was a significant negative correlation between stress perception,loneliness and life satisfaction(r=-0.519,-0.440,P<0.01),and stress perception was significantly positively correlated with loneliness(r=0.568,P<0.01).(2)Stress perception could directly predict life satisfaction(β=-1.217,t=-16.349,P<0.001),and loneliness played a partial mediating role between stress perception and life satisfaction,with the direct effect of-0.931,the indirect effect of-0.285,and the mediating effect accounts for 23.45%of the total effect.Conclusion:Stress perception can not only directly affect life satisfaction,but also affect life satisfaction through the mediating role of loneliness.