Objective To explore the latent classes of developmental trajectories and influencing factors of postoperative nausea and vomiting in patients undergoing open posterior spinal surgery. Methods Patients who underwent open posterior spinal surgery at Peking Union Medical College Hospital between November 2024 and October 2025 were enrolled. Demographic data and clinical data, as well as data on nausea, vomiting, and psychological status from postoperative day 1 to 3, were collected. Latent growth mixture model was used to identify developmental trajectories of PONV. Univariate analysis and binary logistic regression were performed to analyze the influencing factors of the latent postoperative nausea and vomiting classes. Results A total of 201 patients were included. Among them, there were 62 males and 139 females. Two distinct developmental trajectories of postoperative nausea and vomiting were identified by latent growth mixture model: the high risk postoperative nausea and vomiting class (84 patients, 41.8%) and the low risk postoperative nausea and vomiting class (117 patients, 58.2%). Logistic regression showed that a history of abdominal surgery, duration of peak pain on postoperative day 1, a history of previous postoperative nausea and vomiting or motion sickness, time from surgery completion to first oral intake, age and hemoglobin concentration on postoperative day 2 were associated with high risk of postoperative nausea and vomiting. Conclusions Two heterogeneous developmental trajectories of postoperative nausea and vomiting in patients undergoing open posterior spinal surgery were identified using latent growth mixture model, and the independent influencing factors were clarified. Medical staff can formulate targeted prevention and control measures based on the influencing factors of the latent classes, optimize management strategies for postoperative nausea and vomiting in spinal surgery patients, and provide a basis for precise clinical prevention and control of postoperative nausea and vomiting.