Aiming at the problem of serious waste of water resources and serious shortage of labor in the irrigation process of blueberry gardens in hilly areas, a set of intelligent irrigation decision-making system was designed based on Internet of things technology. The system included an information acquisition module, a wireless communication module, an intelligent decision module and an irrigation execution module. The information collection module collected the soil moisture information and environmental information (wind speed, rainfall, temperature, humidity) of the blueberry garden through the soil moisture sensor and small weather station. The wireless transmission module sent the data collected by the information collection module to the server in real time. Analytical processing was carried out, and the calculation result of the intelligent decision-making module was transmitted to the irrigation execution module. In the intelligent decision-making module, based on the historical data collected in the previous stage, the Penman formula and the soil water balance formula were used to establish the irrigation decision model to realize transpiration amount and irrigation amount calculation and real-time monitoring and alarm. The model can determine whether irrigation and optimal irrigation amount were needed according to the data obtained in real time;the irrigation execution module calculated the irrigation time according to the received irrigation information and actual irrigation speed, and performed remote irrigation. Using Visual Studio software as the platform, the monitoring interface of the system host computer was designed to realize real-time detection and storage of soil and environmental parameters, analysis and management of crop water demand status, and real-time warning and irrigation decision. The test results showed that the intelligent irrigation decision-making system can independently judge the crop water demand based on the information collected by the sensor without intervention. When the system found that the crop needed irrigation, it would drive the irrigation device to complete the irrigation, thus realizing remote precision irrigation of blueberry garden. The remote precision irrigation saved manpower and material resources and effectively improved the utilization of irrigation water.