The fire water monitor is one of the most common equipment in the fire fighting. It can eject water jet or water mist by converting the static pressure energy to kinetic energy, and it can also be used for firefighting, cooling, hate insulation and smoke exhaust. The classification and features of fire water monitor were elaborated, and the design of whole structure and key components of fire water monitor was discussed, especially the structure of the flow channel and nozzle. Moreover, the jet characteristics and the influence factors on the jet performances were also investigated in detail. The result shows that the structure and parameters have a big influence on the jet performance. In a certain pressure range，the quantity of flow and outlet velocity increases with the pressure, which can expand the protection scope of the fire water monitor. The relevant analysis can provide some guidance for the design and optimization of the fire water monitor. 