The application relates to the technical field of fire pumps, and provides a pressure-adjustable anti-
backflow fire pump which comprises a pump body provided with a water inlet
pipe and a water outlet
pipe, the water outlet
pipe is provided with an anti-
backflow mechanism, the water inlet pipe is provided with a pressurizing mechanism, a transmission mechanism is arranged between the anti-
backflow mechanism and the pressurizing mechanism, the anti-backflow mechanism at least comprises an anti-backflow pipe and an anti-backflow ring, the anti-backflow ring can move in the anti-backflow pipe, when the anti-backflow ring moves towards the pump body, the pressurizing mechanism can be driven by the transmission mechanism to pressurize the water inlet pipe, and the rotating speed of the
impeller of the pump body can be adjusted according to the moving distance of the anti-backflow ring; the application can determine that the backflow phenomenon occurs in the pipeline by detecting the movement of the anti-backflow ring, and can be timely treated and maintained; and when the anti-backflow ring moves, the rotating speed of the
impeller is adjusted to offset the force of the reverse
water flow, so that the control is stable and convenient.