The invention belongs to the technical field of leather chemical industry and provides a leather fatliquoring agent with anti-mildew and antibacterial functions and a production process thereof. According to the leather fatliquoring agent and the production process thereof, leather can obtain the antibacterial ability during the fatliquoring process, thus the production process can be simplified, the cost can be reduced, besides, environmental protection is facilitated, and meanwhile water resources are saved. According to the technical scheme, the antibacterial leather fatliquoring agent comprises the following components, by weight, of 30-60 parts of chlorinated grease, 30-60 parts of sulfosuccinate salt, 1-40 parts of water, 50 parts of chlorinated grease, 30-35 parts of sulfosuccinate salt and 15-20 parts of water.