Objective To development a nurse educator core competencies scale based on the framework of nurse educator core competencies (NECC) developed by World Health Organization, and test its reliability and validity. Methods The Chinese draft was formed by forward and back translation. We invited experts to evaluate its content validity. After adjustment according to experts' comments, a survey was conducted in 598 clinical nursing educators of university affiliated hospitals in Beijing. Exploratory structural equation modeling (ESEM) was used to evaluate construct validity. Correlation analysis was used to evaluate criteria-related validity. Cronbach's α coefficient was used to evaluate the internal reliability, Spearman-Brown coefficient was usedtoevaluate split-half reliability. Results The scale-level content validity index was 0.810. The model fit results of ESEM were χ²=955.376 (P<0.001), Root Mean Square Error of Approximation=0.048 (0.044-0.052), Comparative Fit Index =0.992, Tucker-Lewis Index=0.987, Weighted Root Mean Square Residual=0.584, and finally extracted eight domains. It's total score had significant correlation with the total score of the competency framework for clinical nursing teachers (r=0.599, P<0.001). Criteria-related validity was good. The overall Cronbach's α was 0.975 and the domains' Cronbach's α were 0.830~0.934. Split-half reliability was 0.910. Conclusions The nurse educator core competencies scale based on the NECC framework had acceptable reliability and validity, which could be used to assess the core competencies of clinical nursing educators in our country.