Demographic dividend is an important driving force for sustainable economic development in developing countries. In recent years, the Chinese government has introduced a series of policies to encourage fertility, but the fertility rate still continues to decrease, which is likely to have a negative impact on China’s economic development. This study proposes a influencing mechanism model of the fertility intentions of the Chinese population from the perspectives of political economics and social psychology, and validates the model through a national sample survey. It is found that family wealth indirectly and positively affects fertility intentions through Chinese people’s subjective class identification; and social media exposure negatively moderates the relationship between family wealth and subjective class identification. This mechanism provides a theoretical explanation for the current special changes in fertility intentions to a certain extent, and also provides a practical basis for policy makers and media regulators to take measures to stimulate Chinese people’s fertility intentions.