Based on structural equation modeling, this paper investigates the impact of expanding higher education levels on human capital accumulation and economic development. The relationship between latent and latent variables is used to estimate the maximum likelihood estimates of scale expansion by calculating unstabilized and stabilized weights. A weighted linear combination of weights in the weights pool is used to construct the SL estimator. Based on the structural equation model, the prediction model of the impact of higher education scale expansion on human capital and economic development is constructed, and four impact hypotheses are proposed. The results show that the rate of return to higher education for expanding the higher education scale is 4.36%. The rate of human capital accumulation is 102.36%, while the level of economic development is 63.89%. It indicates that the positive effect of expanding higher education levels on human capital accumulation and economic development is significant.