Abstract: In order to resist quantum attacks and further reduce the communication cost, a two-round algebraic la-ttice-based multi-signature scheme (TLMS scheme) supporting public key aggregation is proposed. The scheme is provably secure in the random oracle model under the ring version of the short integer solution (Ring-SIS) assumption. Compared with the existing multi-signature schemes, the two-round lattice-based multi-signature scheme needs only two rounds of interactions to generate a multi-signature, requires less computing and communication overhead and can meet the latest security requirements in the quantum era.