This study was to examine the emotion-based coping (emotional awareness, emotional processing, emotional expression) as a mediator in the relations between attachment traumatic experience and psychological acceptance. Participants included 535 adults from Busan, Daegu, Ulsan, Gwangju, Gyeonggi, Gyeongsang, and Jeju who completed the attachment trauma questionnaire, emotion-based coping, and psychological acceptance scale. Results showed negative correlations between attachment trauma, emotion-based coping, and psychological acceptance. In the relationship between attachment trauma and psychological acceptance, emotional awareness, emotional processing and emotional expression were mediated. Based on these results, this not only implies that emotional awareness and emotional experience in psychotherapy can enhance psychological acceptance but also provides useful data specific to attachment trauma.