The study undertakes a diachronic comparative analysis of college students’ Mandarin, dialect, English use status, language aptitude, and language attitudes between 2015 and 2020 using data from a questionnaire of Fujian Province college students. The findings show that: (1) Mandarin’s function and status are increasing, resulting in a situation in which Mandarin is the dominant language and multiple language codes, such as dialects and English, coexist; (2) Mandarin use is increasing, while dialect use is decreasing; (3) Mandarin and English listening, speaking, reading, and writing skills are improving, while dialect listening and speaking skills are deteriorating; (4) Although Fujianese college students have a higher overall opinion of Mandarin, dialects, and English, their views toward Mandarin, dialects, and other languages are deteriorating. Based on this, the paper proposes curriculum ideology and politics in foreign language classes, as well as a variety of strategies to preserve Fujian’s strong dialects and scientifically protect weak dialects and endangered minority languages.