Abstract: The temperature of drinking water is closely related to the growth of sheep in the dry and cold winter in northern China. Unsuitable water temperature will reduce sheep’s appetite, affect the fat condition, hinder the development, thus reducing the economic benefits of breeding. In order to solve these problems, this paper designed a sheep drinking water control system based on programmable logic controller（PLC）, PID algorithm was used to realize constant temperature control of water tank and automatic control of liquid level and outlet valve. The configuration software was used to design human-computer interaction interface, which can complete real-time data display, manual/automatic operation switching and emergency handling. This design could ensure that sheep can drink suitable temperature water in winter, so as to ensure the normal development of sheep and improve the efficiency of sheep breeding in agricultural and pastoral areas.