A scheme is promoted which builds a water-saving irrigation system based on wireless sensor network and fuzzy control technology, we design a wireless sensor network, which consists of sensor node cluster, coordinator node and irrigation controller nodes. Here sensor node cluster is responsible for gathering information such as soil moisture and regularly send it to the coordinator node. Fuzzy controller embedded in the coordinator node takes soil moisture error and error change rate as its input and obtained water demand amount of crops under certain soil moisture through fuzzy inference and fuzzy judge and output it to irrigation controller node. Irrigation controller node controls the implementation of automatic watering. In this article, we describe the implementation scheme of sensor network node and fuzzy controller in detail and design communication protocol for sensor nodes. The experimental results show that the system can quickly and accurately calculate water demand amount of crops, which can provide a scientific basis for water-saving irrigation. In this way, we have made an exploratory study in applying wireless sensor networks and fuzzy control technology to fine agriculture project.