Despite growing evidence of significant role of leader perfectionism in the workplace, few theoretical accounts have delved into intricate dynamics of interpersonal relationships impacted by leader perfectionism, nor have they explored the extent to which these interactions might stimulate employee unethical behavior. From an interpersonal relationship perspective, based on interpersonal complementarity theory, this study proposes a link between leader perfectionism and employee deviant behavior while assessing the mediating impact of supervisor-subordinate relationship conflict, and the moderating influence of employee narcissism.This study employed three-wave surveys, with 335 employees (female 55.8%, 26-35 years old 67.4%, bachelor's degree 61.5%, worked 3-10 years 67.4%, worked with their current leader 1-5 years 66.3%) across 11 enterprises in Chinato reduce the risk of common method bias. On this basis, MPLUS 7.4 was used to test the confirmatory factor analysis of data, and SPSS 24.0 was used to test the hypotheses.(1) Leader perfectionism has a positive effect on supervisor-subordinate relationship conflict. (2) Leader perfectionism has a significantly positive effect on employee deviant behavior via supervisor-subordinate relationship conflict. (3) Employee narcissism positively moderates the relationship between leader perfectionism and supervisor-subordinate relationship conflict, and further positively moderates the indirect effect of leader perfectionism on employee deviant behavior via supervisor-subordinate relationship conflict.This study reveals the mechanism of how employee through deviant behavior as a opposition to leader perfectionism from an interpersonal relationship perspective, which provides theoretical and practical implications for reducing the negative impact of leader perfectionism and employee deviant behavior.