In recent years, the low-quality development of city-customized commercial health insurance cannot meet the healthcare security needs of the masses. Taking the practice of City L in Zhejiang Province as an example, this paper discusses the promotion mechanism and experience enlightenment of the governance model of city-customized commercial health insurance, and analyzes the success factors of city-customized commercial health insurance in City L from three dimensions of value, support and capacity. The study finds that the success of city-customized commercial health insurance not only lies in the value consensus of the government, the public and commercial insurance companies, but also depends on the dual drive of system and technology. City L gives full play to the government's role in regulating the market, finds the combination of commercial insurance and basic medical insurance, realizes the "small incision, big reform" of the healthcare security system, and provides practical and theoretical reference for effectively improving the problem of expensive medical treatment and returning to poverty due to illness.