1. When binding children's medical insurance e-cards, first prepare the household registration books of parents and children, and then download the "National Medical Insurance Service Platform" APP to activate parents' medical insurance e-cards through the "National Medical Insurance Service Platform" APP. 2. Log in to the "National Medical Insurance Service Platform" APP and enter the main interface. You can click on "My" in the lower right corner. 3. Enter the "My" interface and click "Add my family members". 4. After entering the "Binding Method Selection" interface, select "Binding with sfz number" and click "Confirm". Because the system is still not perfect, Xi Medical Insurance Bureau does not recommend to use the Birth Medical Certificate to bind the children's medical insurance electronic certificate. 5. After that, you will enter the "Family Member Add Notification" interface. After reading the consent, select "Read the notice of family members" and click "I have read the consent". 6. In this way, you can enter the "Add Family Members" interface, fill in the children's names and sfz numbers, select Relationship-Children, and click "Click Upload Personal Commitment Letter". 7. Enter the "Personal Commitment Letter Generation" interface and click "Personal Commitment Letter Generation". 8. Enter the "Personal Commitment Letter" interface and click "Start Signing".