Objectives <p>The psychological construct of equanimity, referring to the ability to maintain neutral and unbiased reactions to stimuli regardless of affective valence, currently lacks a validated and comprehensive measurement in the Chinese context. Although the Two-Factor Equanimity Scale (EQUA-S) has been extensively utilized in non-Chinese populations to assess equanimity, its applicability among Chinese individuals remains unexamined. This study, therefore, aimed to translate the EQUA-S into Chinese and evaluate its psychometric properties among Chinese.</p> Method <p>In total, 3581 Chinese participants (<i>M</i>_age = 19.50, 568 males) were recruited to finish an online questionnaire containing scales including the translated Chinese version of EQUA-S and criterion-related variables. The exploratory factor analysis (EFA), exploratory graph analysis (EGA), and confirmatory factor analysis (CFA) were performed. The internal consistency, criterion-related validity, test–retest reliability, and gender differences were assessed.</p> Results <p>According to the results of EFA, EGA, and CFA tests, four problematic items (E-MSM3, 4, 6, 7) have been removed from the original scale. After removal, the adapted Chinese version of EQUA-S exhibited sound psychometric properties (CFI = 0.96, TLI = 0.95, and RMSEA = 0.077 (90% CI [0.069, 0.086])). The internal consistency, criterion-related validity, and test–retest reliability have also been verified.</p> Conclusions <p>The Chinese version of the EQUA-S has been validated for future research.</p> <p>Preregistration.</p> <p>This study is not preregistered.</p>