The utility model relates to the technical field of building outer wall fire fighting, in particular to an automatic water spraying fire extinguishing device for a building outer wall, which comprises a building outer wall body and a mounting groove, and the mounting groove is formed in the inner side of the building outer wall body. An electric telescopic rod is started and drives a connecting plate and a
nozzle to integrally move inwards, so that the
nozzle enters a placement groove, the phenomenon that dust and impurities are easily accumulated at a water spraying opening of the
nozzle due to the fact that the nozzle is located outside all the time is reduced,
corrosion to the nozzle due to direct
irradiation of outside rainwater and
sunlight is avoided, and the service life of the nozzle is prolonged; and the baffle is clamped on the clamping seat through the clamping plate, so that the baffle shields the placing groove, dust and impurities can be prevented from entering, the phenomenon that the spray head is blocked due to accumulation of the dust and the impurities is effectively reduced, the spray head sprays water smoothly during use, fire can be extinguished in time, and the fire extinguishing effect is better.