Aimed at the problems of distributed and heterogeneous data in flood control works, the paper designed and developed a flood control hydrological information integration query system based on browser/server (B/S) mode which was applied to flood control works in Shaanxi province.It proposed object and task of the system and designed overall structure, function and key technology for the system.Application example showed that the system can realize the real time monitoring of hydrological information,the multimode querying of rainfall information and the efficient organization, management and display of the river and reservoir information. Especially during periods of rainstorm in southern Shaanxi in 2010 and severe rainstorm in Yan'an city in 2013, the flood control department got flood information quickly by the system, provided early warning,and let people evacuate quickly and minimize the disaster loss and thus generated great economic benefits. The system has better integration effect and its application is reliable,and can enhance the flood control analysis and rapid response capability.The system has good practical value and application prospect.