Using mainly 6000 Shanghai sample data from the 2017 National Fertility Status Sample Survey，this article analyzes the changes in fertility levels in Shanghai under the background of a comprehensive two-child，as well as the main factors affecting fertility levels and fertility willingness. Combined with in-depth interviews to 55 women of childbearing age and a series of seminars，this article puts forward targeted countermeasures to deal with Shanghai’s ultra-low fertility level，such as：to deep up the possibility of comprehensive liberalization of the fertility policy and response plans，to improve employment-related policies and regulations，to improve the maternity insurance system，to strengthen support for the two-child family，and to provide public welfare matchmaking services.