1. If the books of the children's hospitalization fund are lost, you can contact the relevant institutions and immediately contact the institutions responsible for managing the children's hospitalization fund. The local social security bureau, hospital or insurance company will provide specific guidance and solutions.

2, according to the requirements of relevant institutions, go through the formalities. You need to provide some personal identification documents and related application forms. Ensure that accurate information is provided and the required documents are submitted as required.

If you have any questions or need further help to complete the formalities, you can consult the staff or professionals of relevant institutions.