Objective To construct a standardized nursing system for day surgery patients, providing theoretical support and practical pathways for promoting the standardization, normalization, refinement, and proceduralization of nursing care in day surgery. Methods Using the Hall three⁃dimensional structure model as the theoretical framework, indicators for the standardized nursing system for day surgery patients were preliminarily drafted through literature analysis and multiple rounds of discussions within the research group. An expert consultation questionnaire was designed. Two rounds of Delphi expert consultations were conducted to collect and analyze expert opinions. The structure and items of the system indicators were summarized and optimized, ultimately forming a standardized nursing indicator system for day surgery patients. Results The constructed standardized nursing system for day surgery patients included 3 first⁃level indicators (time dimension, knowledge dimension, logical dimension), 11 second⁃level indicators, and 79 third⁃level indicators. The effective response rates for the two rounds of expert consultations were both 100.0%, with expert authority coefficients of 0.889 and 0.913, and Kendall's coefficients of concordance of 0.171 and 0.179 (P<0.05), respectively. Conclusion The standardized nursing system for day surgery patients, constructed based on the Hall three⁃dimensional structure model, is scientific and feasible. The resulting indicator system is reasonable in content and clear in structure, demonstrating significant value for optimizing day surgery nursing processes and improving the quality of nursing care.