A fire water monitor driven by worm gear with bevel gear was designed based on the theoretical calculations. The classification and features of fire water monitor were elaborated, and the design of whole structure and key components of fire water monitor were discussed. Moreover, the jet characteristics and the influence factors on the jet performances were also investigated in details. The simulation results approximately agree with the expectation effect, which reflects the rationality of the design. The relevant analysis can provide some guidance for the design and optimization of fire water monitor.