Emotions affect one's well-being and mental health, and each person has different personality traits, which influence the emotion regulation process. Better understanding of the relationships between the Big Five personality traits and emotion regulation (ER) strategies are a prerequisite for designing feasible and effective emotion regulation tools from designer's point of view. Thus, this study first conducts a narrative review using a systematic search strategy to gain an understanding of the emotion regulation strategies related to Big Five personality traits for informing the designers in their ER tool design. Second, based on the understanding, it proposes an emotion regulation tool design framework with personality traits for guiding designers/design researchers to develop ER tools. Third, an ER tool is designed and prototyped based on the framework, then it is used in a case study to qualitatively evaluate the framework's usefulness. It is concluded that the framework can provide good guidelines for designers/design researchers to follow when developing ER tools, and in this study the resultant ER tool can better the end-users’ engagement in the ER process.