The present disclosure discloses an atomizing nozzle and a nasal drug delivery device. The atomizing nozzle includes a spray hood which includes a conical hood body and a connecting cylinder provided inside the hood body and connected to the inner top of the hood body, the wall of the connecting cylinder is provided with a bayonet structure or a claw structure for non-detachable snap fit with the corresponding claw structure or the bayonet structure on the outer side of the syringe extending into the connecting cylinder, a columnar end extends from the external tip of the hood body for extending into the internal nasal cavity, the connecting cylinder, the columnar end and a portion of the hood body therebetween jointly form a communicating channel, the front end of the columnar end is provided with a spray hole, and a fluid-guiding cylinder.