Currently, with the increasing frequency of international communication, colleges and universities pay increasing attention to the cultivation of students' oral English communication ability, but the interlanguage fossilization hinders the improvement of learners' oral English ability, which leads to learners' inability to communicate in English accurately and fluently. Therefore, this paper starts from the fossilization of interlanguage, explores its enlightenment and significance to college oral English teaching, in order to effectively improve oral English teaching.