Based on the internal and external constraints of serious disease insurance and commercial serious disease insurance, the logistic model of “whether you are willing to connect with commercial serious disease insurance on the basis of serious disease insurance” and “to understand the objective conditions of the connection between serious disease insurance and commerci”a“ serious disease insurance” is designed. Based on the empirical research on the micro survey panel data of 6 municipal districts in W City in April 2020, the following research results are obtained: among the many influencing factors, “health status,” “per capita family income,” “gender,” “age,” “education level,” “number of children,” “operating rules,” “public value recognition,” “settlement linkage” Internal Factors of “Information Mastery” and “Implicit Restrictions.” Therefore, the family should be insured in the optimal allocation of family members in the order of “family pillar-children-the elderly” and the scientific layout of insurance products on the basis of family per capita income. The government should promote the institutional integration by strengthening the mechanism construction, building an information platform, and optimizing the management system, so as to promote the health big data sharing, and provide a superior environment for the connection between serious disease insurance and commercial serious disease insurance.