In view of the current waste of agricultural irrigation water, an intelligent irrigation system with a Raspberry Pi as the main control device and a cloud platform for monitoring is proposed. This study, with the crop as the experimental object, analyzes the characteristics of the fuzzy control algorithm, Raspberry Pi 4B, sensor technology, HTTP protocol, MySQL database, and OneNET cloud platform and designs an intelligent irrigation system that can automatically irrigate according to environmental conditions. The hardware part of the system can complete the collection of air temperature and humidity and soil humidity. In terms of the software part, considering the low development cost of cloud platform technology that can completely replace the traditional Web in function, applications are developed on the cloud platform, and they can control irrigation and upload the data to the OneNET cloud platform. Meanwhile, they can also import the environmental data into the fuzzy controller to make the irrigation strategy more scientific. In irrigation experimental tests, the maximum irrigation error of the system does not exceed 2%, which means the system can solve the problem of irrigation water waste and therefore has broad application prospects.