This study aimed to examine the relationship between the classroom environment (CE) and university identification (UI) and the chain mediating effects of student engagement and academic achievement (AA). 4,463 Chinese university students were assessed using the classroom environment and UI scales, and measures of student engagement. Results show: (1) a significant positive correlation between a supportive CE, high student engagement, high AA, and high UI; (2) AA plays a mediating role between CE and UI, while student engagement mediates CE and UI; and (3) student engagement and AA play a chain mediating role between CE and UI. This study verified that a positive CE helps strengthen university students' UI, and student engagement, AA, and a series of intermediary roles had a chain mediating effect. Universities should create a positive CE and encourage building good interpersonal relationships between students and others to further increase AA and UI among students.