Objective:To explore the influence of character strengths of nursing interns on work engagement, and the chain intermediary effect of perceived social support and professional identity.Methods:From November to December 2021, 551 nursing interns from 4 ClassⅢ Grade A hospitals in Nanjing were selected by convenient sampling. The General Information Questionnaire, Three-dimensional Inventory of Character Strengths (TICS) , Perceived Social Support Scale (PSSS) , Professional Identity Scale (PIS) and Utrecht Work Engagement Scale (UWES) were used to investigate nursing students. A total of 551 questionnaires were distributed and 511 valid questionnaires were recovered, with a valid recovery rate of 92.74% (511/551) .Results:Among 511 nursing interns, the overall scores of character strength, perceived social support, professional identity and work engagement were higher than the theoretical median. Pearson correlation analysis showed that there were positive correlations between character strength, perceived social support, professional identity and work engagement ( r=0.293-0.666, P<0.01) . The intermediary effect analysis showed that character strength could positively predict work engagement, and the direct effect was 0.271, accounting for 48.57% of the total effect. The intermediary effect of perceived social support between character strength and work engagement was significant, and the indirect effect was 0.147, accounting for 26.34% of the total effect. The intermediary effect of professional identity between character strength and work engagement was significant, and the indirect effect was 0.048, accounting for 8.60% of the total effect. Perceived social support and professional identity had a significant chain intermediary effect between character strength and work engagement, with an indirect effect of 0.092, accounting for 16.49% of the total effect. The total indirect effect of character strength on work engagement was 0.287, accounting for 51.43% of the total effect. Conclusions:The chain intermediary effect of perceived social support and professional identity on the character strengths and work engagement of nursing interns is established. Helping nursing interns identify and use their character strengths, paying attention to the care measures for nursing interns, and scientifically constructing the professional identity training system can enhance the work input of nursing interns.