Objective: This study aims to evaluate the degree of deviation of Guangdong Province's drug online listing prices from the winning bid prices in the alliance centralized procurement, providing a reference for drug price regulation and hospital procurement. Methods: A price deviation index was constructed, and empirical research was conducted using IBM SPSS Statistics 27 software, employing the Mann-Whitney U test and Pearson correlation analysis methods. Results: 58.89% of the drug prices had a deviation degree not exceeding 0.5. Significant differences in deviation degrees were observed among different dosage forms, with suppositories showing a significantly higher deviation than injections, and a weak correlation between online listing duration and deviation degree. However, factors such as the qualification of active pharmaceutical ingredients, the nature of enterprise property rights, the status of market listing, and whether the drug was included in the medical insurance directory did not have a statistically significant impact. Conclusion: It is recommended to incorporate the price deviation index into regular price monitoring, implement refined governance based on key factors such as dosage form, and enforce price control responsibilities for both drug buyers and sellers.