1. Risk control: Revolving loan is a flexible loan form, and borrowers can withdraw funds at any time within a certain amount. In order to control the risk, the bank may require the guarantor to sign the continued guarantee every year to ensure the guarantor's continuous recognition of the loan responsibility and obligation.

2. Legal requirements: According to relevant laws and regulations, the bank can stipulate in the revolving loan contract that the guarantor needs to sign every year. This is to ensure the validity and legality of the contract, so as to safeguard the rights and interests of all parties when necessary.

3. Credit supervision: The guarantor's signature can be used as one of the means for banks to supervise their credit status. By requiring the guarantor to sign every year, the bank can keep abreast of the changes of the guarantor so as to take corresponding measures when necessary.