After analyzing the theoretical basis of dynamic assessment and the necessity of conducting dynamic assessment in college oral English test, we present the design of an experiment for applying dynamic assessment in college English oral test. With freshman non-English majors in South-Central University for Nationalities as subjects, in the experiment we conduct the dynamic assessment in oral English test and study the pre-test and post-test results of the experimental group and the control group. The results show that a dynamic assessment model can fully reflect the zone of proximal development of students' oral English ability, can guide teachers' oral English teaching and develop students' oral English potential.