Based on the CLA model, this paper discusses the autonomous role of formative assessment in students’ English teaching. This paper conducts a statistical analysis of the formative evaluation of English teaching among 40 students in the experimental group during the teaching period of 20 weeks. Research shows that 1) the independent learning behavior, consciousness, motivation and other aspects of the experimental group students have been significantly improved. Results Compared with the control group, there were significant differences in each dimension (P<0.05). (2) The writing skills of the experimental group have been greatly improved. The experimental group was statistically significant compared with the control group (P<0.05). Through the investigation of English teaching, it is found that formative assessment plays a prominent role in improving English teaching. The formative evaluation of English teaching based on the CLA model will promote improving English teaching performance.