Assessment is a very important part in education. It can be divided into assessment of learning, assessment as learning and assessment for learning in terms of evaluation purposes. Assessment is used to improve both teaching and learning, experience a sense of achievement and build up confidence. East China Normal University pronunciation teaching started to apply a summative and formative integrated multi-dimensional assessment model in 2010, but there are still some spaces and room for improvements based on the feedback. Within the framework of dynamic assessment theory, the author conducted the experiment among the freshmen of English majors at ECNU. The results show that with the help of the improved multidimensional assessment system, students pronunciation proficiency and learning motivations have been greatly improved. And with the application of self-evaluation and peer evaluation, students learning habits have been cultivated.