Water security in the Haihe River Basin is an important component of China's ecological civilization and is vital for highquality national development of the country. Considering the development requirement for water security in the Haihe River Basin, we analyzed the problems regarding water security assurance from the perspectives of water resources, water environment, water ecology, and flood disasters. Subsequently, we predicted the development trend of water security in the Haihe River Basin by 2035 through data simulation. On this basis, an overall idea was proposed, that is, assuring water security in the Haihe River Basin by reinforcing measures for protecting water ecology, and highlighting the role of water resources carrying capacity. Focus should be placed on developing capacities regarding (1) systematic allocation and efficient utilization of water resources, (2) comprehensive improvement in water environment, (3) governance and restoration of basin ecology, and (4) prevention and emergency response of flood disasters. Furthermore, we proposed the following suggestions from a technological perspective: (1) implementing new strategies for the conservation and efficient utilization of water resources, (2) ensuring drinking water safety and improving water governance capacities, (3) establishing a water ecological pattern that features people-water harmony, and (4) developing a flood disaster prediction and response mechanism.