Investigating the contributing factors of post-traumatic stress symptoms (PTSS) has always been an important topic in the field of traumatic psychology research. The current study explored the influences of pandemic/epidemic experiences, meditation experiences, and trait mindfulness on PTSS and the mediating role of emotional resilience during the COVID-19 pandemic. A total of 522 participants in Hubei province completed the Five Facet Mindfulness Questionnaire, the Adolescents’ Emotional Resilience Questionnaire, and the PTSD Checklist for DSM-5. The results showed that (1) participants who had family or friends diagnosed with COVID-19 scored higher on avoidance. (2) Participants who had family or friends had been diagnosed with SARS or H1N1 scored higher on PTSS. (3) Participants with meditation experience scored significantly higher on all dimensions of PTSS, other than avoidance. (4) The mediating role of recovering from negative emotions in the relationship between trait mindfulness and PTSS was significant (95%CI= [-0.212, -0.094]), while the generating positive emotion was not significant (95%CI= [-0.050, 0.071]). Individuals with pandemic/epidemic experience are more likely to have a high level of PTSS. Individuals who have meditation experience also express a higher level of PTSS, which may be a result of the quality of meditation. Trait mindfulness and the ability to recover from negative emotions were protective factors against PTSS.