The skyline query in road networks has important application value in the fields such as intelligent transportation, point of interest discovery, and location services. In order to solve the problem of low efficiency of skyline queries in road network environment and the lack of privacy of query results, a differential privacy-based skyline query method in road network environment is proposed. In this method, first, aiming at the characteristics of large data amount and complex data in the initial dataset of road network environment, the dataset is preprocessed, and three pruning rules are proposed based on the properties of the skyline layer divided by distance attributes and the Voronoi diagram of the road network. Next, based on the pruning rules, a dataset pruning algorithm in road network environment is proposed, which can effectively filter out a large amount of redundant data. Then, for the filtered dataset, a storage method of grid index is utilized to save the storage space. Furthermore, a skyline extension tree based on grid index is designed, and an algorithm for querying global candidate skyline point sets is proposed based on the extension tree and the corresponding pruning rules. Finally, for the query result set, a differential privacy budget allocation model is employed to allocate privacy budgets, and a result set publishing algorithm based on information divergence is proposed, thus effectively improving the privacy of data information. Experimental results show that the proposed query method achieves a query accuracy of more than 99%. It improves the query efficiency by more than 10%, as compared with the traditional skyline query methods in larger datasets. When the total differential privacy budget is 0.01, 0.10, 0.50 and 1.00, the relative error of the proposed privacy budget allocation method is lower than that of the equal difference and equal ratio allocation methods.