Objective To develop and preliminarily evaluate a pain management module based on the Clinical Care Classification (CCC) as a part of the nursing clinical decision support system (CDSS). Methods A research team was formed to search relevant evidence about pain management for hospitalized patients and to formulate knowledge base for pain management and care.Items in the knowledge base were coded based on the CCC, then association rules and an interactive human-machine interface were developed for pain management in the nursing CDSS.The pain management module was optimized based on users′ feedbacks in the pilot wards before clinical implementation. Results After implementation of pain management module of CDSS, the rates of performing pain assessment at admission, daily pain assessment, reassessment, observation of routine/temporary analgesia adverse reactions were significantly improved (P＜0.05，P＜0.01). Conclusion Designing pain management module as part of the nursing CDSS, achieves closed-loop management of pain in hospitalized patients and improves the quality of nursing records, thus to standardize pain practice in nursing.