The topic of "fear of birth" has been hotly discussed by netizens. In response to this phenomenon, the country has introduced a series of policies to encourage fertility, but China's fertility rate continues to decline and even faces the fertility crisis of "low fertility trap".The decline of fertility rate will bring a series of impacts to the development of a country, such as the prominent aging problem of the population, the decrease in the number of working population, and hindering economic development, etc. (Cai, Meng, Lin , Qin, 2019). In order to alleviate the negative impact of declining fertility rate on national development, China has introduced the corresponding fertility policy, from the launch of the "single two-child" policy in 2013 to the official implementation of the "universal two-child" policy in 2016. However, Shang et al. (2019) found in their research that these fertility policies had little effect. The fertility rate did not increase, but became lower and lower. Some researchers believe that this is a sign that China is about to enter the "low fertility trap" (wu, 2019). The decline of fertility rate in China and even in the world is an established fact. The lack of fertility desire of people of child-bearing age is a prominent social problem at present. So it is necessary to explore the reasons why the fertility rate of people of child-bearing age in China continues to decline has been lifted, find out the factors that affect the fertility desire of the population of child-bearing age and their boundary conditions, and put forward corresponding solutions to improve the fertility rate. So, apart from the restrictions on the birth policy, what causes the decline of the national desire to have children? This study examined the effects of fertility age limitation on fertility intention and the boundary conditions of socioeconomic status. Fertility age limitation refers to the sense of fertility urgency caused by individuals' perception of the length of time between their actual age and the optimal reproductive age. Study 1 investigated the relationship between fertility age limitation and fertility intention through two sub-studies. Study 1a conducted a questionnaire survey among 400 individuals of in-service childbearing age. In Study 1b, an online experiment was conducted on 500 people of child-bearing age, and the optimal age to prime the second child was 40 years old. In Study 2, 100 graduate students were recruited to manipulate fertility age limitation: The optimal fertility age was 26 years (vs. control group). The results showed that The closer the subjects' actual age was to their optimal age, the stronger their desire to procreate was; The socioeconomic status had significant moderating effect between fertility age limitation and fertility intention. This study has enriched the literature on fertility intention from the perspective of psychology, and has certain theoretical guiding significance for improving fertility intention of people of childbearing age, increasing total fertility rate in China, and getting out of the "low fertility trap".Finally, the paper discussed the significance of research concerning fertility age limitation and fertility intention, as well as the future direction of research in this area.