After the reform and opening up, middle schools in various regions of China have generally implemented a hierarchical and divided teaching method. However, whether the introduction of hierarchical classification has improved students’ learning conditions and what are the differences between different classification policies have not been empirically answered. This paper used baseline data from the China Education Tracking Survey (CEPS) and adopts DID model to find that hierarchical teaching improves the difficulty of middle school students’ curriculum learning. It is mainly reflected in a significant increase of 5% to 9% in the difficulty of learning English courses, and an increase but not significant in the difficulty of learning Chinese and mathematics courses. Based on the analysis of students’ learning abilities, the hierarchical classification system has brought significant negative effects to students with learning abilities at the middle and lower levels, while the response to other students is not significant. At the same time, this paper analyzes the learning effects of different periods of class stratification and finds that if class division is necessary, the earlier the class division time, the better. CCS CONCEPTS • Network Management • Information retrieval.