The invention discloses a multivariable signature method capable for resisting a forged signature 
attack, which is characterized in that by adding a vector called as signature additional value, a 
verification condition related to internal information is added during signature 
verification, so that the forged signature 
attack can be revisited effectively. The multivariable signature method particularly comprises three stages of data pre-
processing, signature generation and signature 
verification. By taking a multivariable 
public key cryptosystem as a theoretical basis, a message signature and verification scheme is established according to a multivariable polynomial equation set in a finite field, so that the model defect of the conventional multivariable signature scheme is overcome, and under the condition of resisting a 
quantum attack, signature verification not only is dependent on public key verification, but also involves a user's legal private key. Therefore, the multivariable signature method can provide a basic technological support for 
information security of the 
quantum computer era and establishment of a trust 
system, and is suitable for secure 
digital signature in the 
quantum computer era; and moreover, due to relatively high efficiency and security, the multivariable signature method is particularly suitable for occasions where memory space and 
operation time are limited.