Legal analysis: If the guarantor of the guarantee contract does not sign, the contract is invalid.

Legal basis: "People's Republic of China and Civil Code"

Article 490: Where the parties conclude a contract in the form of a contract, both parties shall sign, seal or The contract is formed when the fingerprint is pressed. Before signing, sealing or fingerprinting, one party has performed its main obligations and the contract is established when the other party accepts it. Laws and administrative regulations stipulate or the parties agree that a contract should be concluded in written form. If the parties do not use written form but one party has performed its main obligations and the other party accepts it, the contract is established.

Article 502 A contract established in accordance with the law shall take effect from the time of its establishment, unless otherwise provided by law or otherwise agreed upon by the parties.