In the summer, high temperature is a key factors of affecting milk yield,and spray cooling is the most effective way to decrease cows body temperature and reduce their heat stress response. This study designed a practical and effective automatic cooling system, In this system,a PC software which is based on the MODBUS protocol was designed by LabVIEW, the sensor information was collected by the MODBUS analog quantity acquisition module, the opening and closing time sprinkler are controlled by the temperature and humidity indexes (THI), which implement the automatic cooling of dairy farm. The test results show that the system has good cooling effect. Compared with the control group respiratory rate of the test group with sprinkler cooling drops maximum of 18 beats per min,and a minimum of 1 beats per min.