When formulating the national line, the Ministry of Education will first consider the national postgraduate enrollment plan, the number of applicants and the overall quality of students. Combined with the national strategic needs, the distribution of educational resources and the development goals of higher education, the admission standards of various categories and majors are determined. This paper analyzes the overall situation of the results of the national unified examination and the joint examination, including the distribution, difficulty and changing trend of the results of different subjects over the years, so as to determine the reasonable threshold of the score line.