Background Undergraduate nursing students' interpersonal skills are closely related to their clinical nursing competence, yet research on the effects of interpersonal sensitivity on interpersonal skills and its mediating mechanisms is not found. Objective To investigate the effects of interpersonal sensitivity on undergraduate nursing students' interpersonal skills and the mediating role of self-efficacy and subjective well-being. Methods This study was a cross-sectional design conducted in Henan Province, China, from March to April 2024, using convenience sampling method, questionnaires using Interpersonal Competence Questionnaire, Interpersonal Sensitivity Scale, General Self-Efficacy Scale, and Index of Well-Being were administered to 745 undergraduate nursing students. The resulting data were analyzed using SPSS 25.0, and structural equation modeling was constructed using Amos 26.0 to explore the mediating role of self-efficacy and subjective well-being between interpersonal sensitivity and interpersonal skill. Results The interpersonal skill of undergraduate nursing students was at a moderate level (M +/- SD: 116.16 +/- 29.383), and interpersonal sensitivity had a significant negative effect on interpersonal skill (r = -0.373, p < 0.01). Self-efficacy and subjective well-being acted as chain mediators between interpersonal sensitivity and interpersonal skill, accounting for 6.51% of the total effect. Conclusion Nursing educators should emphasize the effect of interpersonal sensitivity on interpersonal skills and take feasible measures to improve the self-efficacy and subjective well-being of undergraduate nursing students to promote their interpersonal skills.