To prove the B-level qualification of catering enterprises, you usually need to follow the following steps:

1. Inquire about relevant laws and regulations: understand the catering laws and regulations and qualification requirements in your region. This can usually be obtained through the official website of government departments or relevant industry associations.

2. Prepare necessary documents: prepare relevant documents and supporting materials according to the requirements of laws and regulations, such as enterprise registration certificate, food business license, hygiene license, tax certificate, etc.

3. review and evaluation: submit the prepared documents to relevant regulatory agencies or certification bodies for review and evaluation. They will check whether your enterprise meets the requirements of relevant standards and regulations.

4. Payment of fees: Some regions may need to pay fees for qualification examination and certification.

5. audit results and certificate issuance: according to the audit results, you will receive corresponding qualification certificates or documents to prove that your catering enterprise has B-level qualification. Catering enterprises refer to commercial entities engaged in catering-related businesses such as food production, sales and service. It can include various types of restaurants, coffee shops, fast food chains, bars, nightclubs and other places.