Humanistic caring (HC) is a key ability that nurses need. We aimed to explore factors related to humanistic caring ability (HCA) among Chinese nursing students and the association between professional identity (PI) and HCA. A cross-sectional survey was conducted. HCA of Nursing Undergraduates Assessment Scale (HCANU) and PI Scale for Nurse Students (PIQNS) were displayed. Linear regression analysis and Pearson correlation analysis were used. Education ([beta] = -0.161, P = 0.009), dimensions of professional self-image ([beta] = 0.271, P = 0.028), career choice independence ([beta] = 0.228, P < 0.001), and social comparison and self-reflection ([beta] = -0.102, P = 0.180) were independent predictors of HCA. PI (r = 0.578, P < 0.001) was associated with HCA. An association between PI and HCA has been found among nursing students. PI is an important consideration in the development, implementation, and evaluation of interventions for HCA.