This study focused on the design and benefit analysis of water and fertilization integrated intelligent irrigation system based on the Internet of Things to save water and labor. This system includes eight components: intelligence platform (information center), field irrigation control system, intelligent fertilization system, farmland meteorological environment monitoring systems, remote telemetry system of soil moisture, the remote pipeline pressure and flow monitoring system, remote video monitoring system of crop condition, and energy efficiency monitoring system. In the process of application, according to the results of sensitivity analysis, we found that the annual benefit is the most sensitive factor in its economic internal rate of return. Comparing with common drip irrigation, the investment of the system is large, but its annual benefit improvement can make higher economic internal rate of return. Therefore, greatly enhance the benefits of irrigation system creation ability. Application effect showed that the water and fertilization intelligent irrigation system based on the Internet of Things has remarkable water-saving effect. In addition, the system has a good application prospect along with the advance of science and technology and the development trend of water resources informatization.