Identifying the lowest effective opioid dose that achieves rapid pain relief while minimizing side effects is a principal objective in postoperative multimodal analgesia strategies. This study aims to determine the optimal analgesic regimen and dosage by assessing the clinical efficacy of oliceridine for postoperative pain management. It also evaluates oliceridine's contribution to accelerated postoperative recovery, examining aspects such as postoperative pulmonary complications, gastrointestinal function, nausea and vomiting, cognitive function, and emotional distress. Furthermore, the study integrates microbiomics and metabolomics to investigate the underlying molecular mechanisms by which oliceridine promotes rapid postoperative recovery. This research will broaden the clinical data and potential applications of oliceridine, addressing gaps in the field and enhancing practical knowledge. Moreover, this is the first time a clinical study combining multiple omics approaches will provide a comprehensive theoretical foundation for its clinical benefits.