Childhood maltreatment experiences are closely related to aberrant emotional processing that may be associated with resilience. Although different stages of emotion processing, such as identification of emotion, selection of regulation strategies, and implementation of regulation strategies, can be affected by maltreatment experiences, it is still unclear which part of emotion processing is closely associated with the vulnerability the victims have. In this study, we investigated the effects of different emotion regulation strategies on psychological resilience. Among a total of 360 participants, 89 maltreatment and 112 no-maltreatment subjects were included in the analysis of a questionnaire survey. An additional cognitive reappraisal task was conducted in 25 maltreatment and 25 age-, gender-, and education-matched no-maltreatment subjects. The maltreatment group reported greater difficulties in identifying emotion, such as lack of emotional awareness or clarity. Moderation analysis revealed that lack of emotional awareness has a significant effect on the relationship between childhood maltreatment experiences and low psychological resilience. In the cognitive reappraisal task, the maltreatment subjects reported higher negative valence scores on ambiguous neutral pictures than the no-maltreatment subjects. Our results suggest that difficulties in emotional awareness, especially with ambiguous emotional cues, play a crucial role in low resilience in maltreatment victims.