[Purpose/significance]Exploring the generation mechanism and influence of social media fatigue among youth group is beneficial to recognize the change in their social media usage behavior under the background of the mobile Internet era, and has positive guiding significance for building healthy and sustainable social media platform ecology.[Method/process]Establishing research model based on Cognition—Affect—Conation Pattern, this study analyses the data collected from 353 valid questionnaires by using structural equation model through Amos.[Result/conclusion] It is found that poor intergenerational communication, negative social comparison, awakening from immersion, few interaction and overload information have significant impact on social media fatigue, while impression management and missing anxiety have no significant impact on it. Social media fatigue is likely to lead to the passive use, such as keeping silent, neglecting, shielding from disturbance and hiding knowledge.