[Purpose/significance] The phenomenon of social media addiction is becoming increasingly prominent. The paper clarifies the mechanism of users' discontinuous use social media due to addiction, which can provide a new perspective for users to reduce problematic use of social media. [Method/process] Based on self-discrepancy theory, a model of social media users' discontinuance intention was constructed. The paper reveals the interaction mechanism among social media addiction, negative emotions (social anxiety, depression) and discontinuance intention, and analyz? es the moderating role of self-efficacy in the relationship between social anxiety, depression and discontinuance inten? tion. A total of 399 valid data were collected from an online questionnaire. Partial least squares structural equation mod? elling (PLS-SEM) is applied to carry on the empirical analysis of the model. [Result/conclusion] The results showed that social media addiction puts a positive influence on social anxiety, depression, and discontinuance intention; Social anxiety positively affected depression and discontinuance intention, and depression positively affected discontinuance intention. Self-efficacy had a moderating effect on the relationship between social anxiety, depression and discontinu? ance intention.