This paper examined the impact of urban housing price increases on child dependency ratio and heterogeneity using data from 285 prefecture-level cities in China from 2007 to 2016. The study found that the rapid rise in urban housing prices significantly reduces the overall child dependency ratio in the city and exacerbates the imbalance of the demographic structure. Further research found that the contradiction between urban housing prices and population structure is more prominent in the eastern coastal cities and cities with larger populations, which is related to the “distortion degree” of the real estate market mechanism. The analysis of the intermediate mechanism showed that the rise of urban housing prices led to an increase in per capita savings and per capita consumption, and an obvious “squeezing effect” and "wealth effect" on the fertility resources, which will have an inhibitory effect on the overall fertility level of the city by the resource mismatch mechanism, leading to an imbalance in the population structure.