To provide a throttle control device for a fire engine pump which can smoothly and minutely control valve opening.

A throttle valve of a fire engine pump is driven by a DC motor. Pulse voltage composed of a plurality of controlling states having different duty ratios from each other is applied to the DC motor. Duty frame F of the pulse voltage can be varied in shifting of control stages or within each control stage. It is thus possible to control a throttle opening minutely with satisfactory follow-up property, and automatically control discharge pressure and a discharge flow amount with accuracy.