The construction of integrated irrigation and drainage project is one of the important measures for increasing water and fertilizer utilization efficiency, reducing the impact of drought and flood disasters, and improving grain yield. In recent years, people gradually realize that irrigation and drainage are two closely connected parts, therefore the research and related construction of farmland drainage projects are increasing. In the early stage of the irrigation and drainage system application, people only focused on improving the drainage efficiency, and then began to pay attention to the environmental impact. Finally, the system developed into the integrated system combining water-saving irrigation and new drainage engineering. By controlling the system operation process, irrigation and drainage integration project will have a certain impact on the soil moisture content, groundwater level salinity, and in turn affect the water absorption and physiological growth process of the crops. A reasonable integrated irrigation and drainage project can promote the growth of crops and increase the yield. The functions of integrated irrigation and drainage project in southern and northern China are different. In the south, waterlogging and seepage control are the main functions, whereas improving drought resistance and controlling soil salinization are the main functions in the north. In addition, there are some issues to be addressed, such as large demand for funds in the early stages, imperfect operation and maintenance management, and technical difficulties in system operation. In the future, the integrated irrigation and drainage engineering should be developed towards the pipe network, informatization and automation, so as to further save agricultural water and reduce fertilizer waste, realize the modernization of irrigation and drainage integration projects.