The current research was conducted with the aim of the effect of attachment style on emotion regulation with the mediating role of identity style. The research method was descriptive and structural equation analysis. The statistical population of the research was all second year high school students of Kashan city in the academic year of 1400-1401, of which 500 people were selected by random cluster method. Data were collected based on three questionnaires: Gross & Jan (2003) Emotional Regulation Inventory, Identity Style Scale (6G-ISI) and Collins and Reid (1990) Attachment Style Questionnaire. The data are obtained by structural equation modeling and using Laserl 8.8 and 26 spss software. analyzed. Based on the results, secure attachment style at a significance level of 0.01, avoidant attachment style at a significance level of 0.05, and ambivalent attachment style at a significance level of 0.01 directly predicted emotion regulation. Among the three attachments, secure attachment style predicted emotion regulation at a significant level of 0.01, with the mediation of identity styles. Informational identity style at a significance level of 0.01, confused identity style at a significance level of 0.05 directly predicted emotion regulation. Among the three attachments, only the secure attachment style at a significance level of 0.01 had a significant role in predicting the normative identity style. According to the results of this study, emotion regulation is one of the most important constructs of educational psychology and an important factor in determining mental health and successful performance. It is in education that the factors affecting emotion regulation and its antecedents should be identified. Planning for training and holding educational workshops in this field in schools is suggested for students.