The invention discloses a distributed hydrological detection system, which comprises a general control module, a reservoir alarm module, a city alarm module, an alarm rating module, a data processingmodule, an information filtering module, a reservoir information acquisition module, a first monitoring module, an early warning module, a city information acquisition module and a second monitoring module, wherein the first monitoring module is composed of a reservoir rainfall monitoring module, a water flow velocity monitoring module, a reservoir flow monitoring module, a reservoir water level monitoring module and a silt monitoring module; the second monitoring module is composed of a city rainfall monitoring module and a city water level monitoring module; and the general control module isin communication connection with the reservoir alarm module and the city alarm module. The distributed hydrological detection system can carry out more accurate risk rating through detecting hydrological information so as to increase the accuracy of risk alarms and reduce the loss when disasters occur. In addition, the system can carry out hydrological detection on cities and reservoirs at the same time, so that the application of the hydrological detection system is more extensive.