Objective To investigate current status of knowledge, attitudes, and practices (KAP) regarding humanistic care among oncology nurses and analyze the influencing factors, and to provide a reference for developing targeted measures to improve oncology nurses′ KAP regarding humanistic care. Methods From January to April 2025, oncology nurses from 113 hospitals in China were selected via convenience sampling method. A general information questionnaire and the Humanistic Care Knowledge, Attitudes, and Practices Questionnaire for Clinical Nurses were used for data collection. Results A total of 2,158 valid questionnaires were collected. The overall standardized score of humanistic care KAP among oncology nurses was 89.96±11.09, with scores of 86.90±13.65 for knowledge dimension, 89.45±13.15 for attitudes/beliefs dimension, and 92.85±10.25 for practices dimension. Multiple linear stepwise regression analysis revealed that job position, level of family support for work, degree of passion for nursing, job satisfaction, level of emphasis on self-care, and participation in humanistic care training were significant factors influencing the level of humanistic care KAP (all P<0.05). Conclusion The overall humanistic care KAP among oncology nurses is generally satisfactory, though the knowledge dimension still needs to be improved. Multiple factors influence the level of humanistic care KAP. It is recommended to strengthen humanistic care training for oncology nurses, particularly focusing on areas with knowledge gaps, while also enhancing job satisfaction, self-care awareness, and family support to further improve their humanistic care KAP.