Objective:To explore the current situation of tacit knowledge sharing among nurses and analyze its influencing factors.Methods:From March to June 2023, convenience sampling was used to select 437 nurses from three ClassⅢ Grade A hospitals in Changsha as the research subject. The survey was conducted using the General Information Questionnaire, Tacit Knowledge Sharing Scale, Person-Organization Fit Assessment Scale for Nurses, and Maslach Burnout Inventory. The R software randomForest package was used to construct a random forest model and rank the importance of factors influencing tacit knowledge sharing; LASSO analysis was used for variable selection, and the selected variables were analyzed for influencing factors using multiple linear regression.Results:A total of 437 questionnaires were distributed, and 434 valid questionnaires were collected, with an effective response rate of 99.31% (434/437). The Tacit Knowledge Sharing Scale score of 434 nurses was (13.09±3.03). The random forest algorithm showed that the top four independent variables in importance ranking were occupational burnout, professional title, working years, and person-organization fit. Multiple linear regression analysis indicated that occupational burnout, professional title, and person-organization fit were the main influencing factors of tacit knowledge sharing among nurses ( P<0.01) . Conclusions:The tacit knowledge sharing among nurses needs to be improved. Nursing managers can enhance the tacit knowledge sharing among nurses by reducing their professional burnout, improving the system of professional title promotion, and enhancing the fit between persons and organizations.