Hello, thank you for asking. Whether the criminal appeal requires the signature of the defendant needs to be determined according to the actual situation. The right of appeal belongs to the defendant, so the signature of the appeal should be signed by the defendant. However, if the defendant has authorized the entrusted lawyer to appeal in writing and given the entrusted lawyer the right to sign on his behalf, the lawyer can sign on his behalf according to the authorization contract and submit an appeal to the court. I hope I can help you!