To resist quantum computing attacks and reduce the risk of private key leakage of users in proxy signatures, this study proposes an identity-based proxy signature scheme on lattices. This scheme is designed based on the secure and efficient GPV signature framework. The verification public key is generated by combining the user identity information. The lattice basis delegation technology is used to generate the private key for the user signature, and the bonsai tree delegation algorithm is adopted to improve signing efficiency. The security of the scheme is based on the shortest integer solution (SIS) assumption. It satisfies the security properties of identity-based proxy signatures and has existential unforgeability under random oracles and quantum random oracles.