1. First of all, you need to know the conditions for handling large credit cards in public institutions. Different banks and institutions may have different requirements.

2. Secondly, choose a bank that can handle large credit cards: choose a bank or institution with good reputation and high service to handle large credit cards for institutions.

3. Then, prepare materials: generally, you need to provide some basic personal and work information, such as ID card, work certificate, salary flow, company certificate, etc.

4. Finally submit the application: according to the requirements of the selected bank or institution, fill in the credit card application form and submit the corresponding materials.