A mobile fire extinguishing device includes a motorbike having a base connected to a rear end thereof, and a foam-type fire extinguishing device is connected to the base. Two support units extend from two sides of the base respectively and each support unit has a retractable support rod. A support stand is pivotably connected to the rear end of the base and is positioned either at a retracted first position or an extended second position. When the two support rods are extended, the motorbike is lifted upward and the rear wheel of the motorbike is lifted from the ground. When the support stand is pivoted to the second position, the two support units are retracted, the support stand contacts against the ground so that the motorbike is stable on the ground to bear the reaction force due to the action of the foam-type fire extinguishing device.