The invention discloses an agricultural automatic irrigation system which comprises a cloud computing center, a PC software client, a server group, a mobile phone terminal, a weather station, a soil moisture content station and an intelligent irrigation information management system. By adopting the agricultural automatic irrigation system, environmental information of agricultural facilities canbe monitored in real time, and a reasonable irrigation scheme can be formulated, so that not only are water resources saved, but also a balanced environment is provided for long-term healthy growth ofcrops in the agricultural facilities. The agricultural automatic irrigation system has the advantages of low power consumption, convenient configuration, low cost, wide application range and the like, and can be applied to agricultural industrial environments such as orchards, botanical gardens, public green areas, sightseeing agriculture, flowers, nursery lands and the like. Through the detection and analysis of soil moisture content and climate, the implementation of intelligent sprinkling irrigation is realized, the crop quality and the yield are improved, labor costs are saved, the productivity is improved, the safety of agricultural products is guaranteed and agricultural ecological benefits are promoted; and through the establishment of an agricultural information cloud platform, information on crop growth can be obtained for data analysis and mining, an expert database can be provided, and the agricultural technology can be shared.