Abstract: There has been a contradiction between students'strong desire to express themselves and their lack of practical expression ability in the postgraduate oral English classroom for a long time. It is an urgent task to set up a reasonable oral classroom construction system. Constructing an ecological postgraduate oral English class based on setting ecological factors can guide students to find lexical chunks, grammar and logic, so as to achieve a high degree of unity in content and form of expression. Moreover, students' learning results are evaluated through the calculation of circulation rate, turnover rate and turnover time and then are fed back in time, so that teachers and students can adjust teaching and learning strategies in time to achieve the teachinggoal.