Abstract: Water and fertilizer integration system is one of the core contents of smart agriculture, which can achieve water saving and fertilizer saving, time saving and labor saving, and improving quality and efficiency in agricultural irrigation．Water and fertilizer integration system mainly consists of components such as a controller, filter, and Venturi fertilizer absorber, as well as modules for control, water and fertilizer supply, mixing, and detection．Structural characteristics and working principles of water and fertilizer integration system was discussed．Based on process of regulating water and fertilizer conductivity and pH value, control objects and strategies of water and fertilizer integration system were elaborated．By utilizing field collection systems, irrigation control systems, integrated water and fertilizer systems, cloud servers, transmission systems, wireless sensor networks, and remote monitoring platforms, real-time monitoring and transmission of front-end information can be achieved．Based on integrated control system of water and fertilizer, remote measurement and control system, as well as integrated system of drip irrigation and micro spray irrigation, key technologies and application modes of water and fertilizer integration were explored．Water and fertilizer integration system based on internet of things could provide technical support for modern agricultural construction and smart water conservancy construction．