From the perspective of educational demography, high-quality student-in-school pattern is an important part of the high-quality development of education. Under the requirements of high-quality development of education, high-quality student-in-school pattern should have the characteristics of “five highs”: high attendance among school age population, high equity among groups, high balance among regions, high efficiency at all levels of school, high expected years of schooling. The data from the four national censuses from 1990 to 2020 show that the evolution of our country’s student-in-school pattern has the following characteristics and shortcomings. (1) The basic education age group has basically achieved “high attendance among school age population”, and insufficient school attendance is mainly manifested in the tertiary education age group. (2) The inter-group differences represented by gender differences have gradually become fair, and the trend that men’s inter-group differences will be lower than women’s in the future should deserve attention. (3) The pattern of regional imbalance in student-in-school pattern has not changed, and there is a large gap between urban and rural areas in the age group of high school and above. (4) At present, all levels of student-in-school pattern have entered a stage of development towards “high efficiency”, but overage school attendance is still prominent. (5) The expected years of schooling is still nearly one education level away from developed countries, the main nodes restricting “high expected years of schooling” in our country are the consolidation of student-in-school rate in high school and the improvement of the graduate enrollment rate. The research suggests that it is urgent to make up for the shortcomings of students-in-school pattern in the basic education, focus on promoting the development of tertiary education, to promote our country’s student-in-school pattern to the second and third high-quality progressive upgrades with the goal of entering the forefront of innovative countries in 2035.