Abstract: Chinese-style modernization is a type of modernization where material and spiritual civilizations are coordinated. In the path to modernization, intensifying the promotion of the national common language reflects a new development trend where the cause of language in the new era is closely connected with national development strategies. The popularization of the national common language in ethnic regions is not only an important support for building a high-quality education system but also a powerful measure for implementing the rural revitalization strategy, and it is also a basic tool of national education under Chinese-style modernization. This article focuses on primary and secondary school students in the Tibetan and Yi ethnic regions during the compulsory education stage in Southwest China. Using R 4.3.0 statistical software and the LSD multiple comparison method, this study conducts an error measurement analysis of the pronunciation of consonants, vowels, tones, tone changes, retroflex, and neutral tones in the national common language among minority students across four school stages. It finds that although Tibetan and Yi students have basically reached the requirements of the national common language level set by the curriculum standards, their phonetic errors still show significant differences between school stages. Although there are no ethnic differences in the first stage of schooling, there is a noticeable urban-rural difference. As students progress through school stages, the average error rate gradually decreases. To effectively improve the education quality and language abilities of minority students, it is necessary to recognize the learning characteristics and differential feedback of the national common language among students at different school stages, especially to strengthen the improvement of the national common language level of students in the first stage of schooling, particularly in rural schools.