In view of the problems of traditional irrigation, such as waste of water resources and waste of human resources, the paper presents a design scheme of intelligent irrigation system based on LoRa. LoRa is an ultra-long-range wireless transmission scheme based on spread spectrum technology to maximize communication distance and lower power consumption. The automatic or manual irrigation mode is designed by designing the software of light harvesting, air temperature, humidity and soil moisture based on LoRa communication technology, communication gateway, combined water valve control unit and intelligent management of PC-side irrigation control software. The experimental data show that the designed irrigation system has flexible irrigation methods, intelligent and efficient, practicality, and meets the needs of the system, so as to achieve refined management of irrigation operations.