The invention relates to an anti-freezing device, in particular to a firefighting water anti-freezing device for a firefighting truck. The firefighting water anti-freezing device for the firefighting truck is good in anti-freezing effect, saves time and labor and is high in practicability, and comprises a water tank and the firefighting truck. The water tank is arranged on the right side of the top of the firefighting truck ad comprises a supporting rod and the like. A baffle is arranged in the middle inside the water tank. A second small hole is formed in the lower portion of the baffle. The left side of the bottom inside the water tank is connected with a second spring. The upper end of the second spring is connected with a second push plate. The right end of the second push plate makes contact with the left side of the baffle, and the left end of the second push plate makes contact with the inner wall of the left side of the water tank. The firefighting water anti-freezing device for the firefighting truck achieves the effects of being good in anti-freezing effect, saving time and labor and being high in practicability. When the firefighting truck is not used, the firefighting water anti-freezing device for the firefighting truck can prevent water in the water tank from freezing by controlling rotation of a gear motor.