The present invention provides a bispecific antibody and a use thereof. The bispecific antibody comprises a first protein functional zone and a second protein functional zone. TIM-3 full-length antibody of targeting TIM-3 corresponding to the targeting TIM-3 in the first protein functional zone has a weak bonding activity with Macaca TIM-3, has strong bonding activity with Marmoset and human TIM-3, and can activate the killing effect of a human NK cell on the tumor cell. The bispecific antibody reserves the activity of a single TIM-3 antibody of activating PBMC(NK) to kill the tumor cell while reserving the original activity of the other protein functional zone, and can achieve the same activity of being combined with two molecules or better activate the activity of a T lymphocyte.