High school is a link between compulsory education and higher education in China. The precise projection of high-school population is also a key premise of the rational high-school educational-resource allocation which is of importance to educational quality. Improving the education quality can promote the population quality and increase the accumulation of human capital to create a new geographic dividend and contribute to the new development model of dual circulation. Encouraging governments at all levels to increase financial investment in education is a demand-side dimension to study the demand for high-school educational resources. When promoting human capital accumulation, China should transform the reliance of its economic growth from “demographic dividend” to “talent dividend” to build a new development model of dual circulation. This paper built a Leslie model by matrix laboratory (MATLAB) to predict the high-school population and study the demand for high-school educational resources.