Two-grade atomization nozzle applicable to fire extinguishment of power transmission line mountain fire

The invention discloses a two-grade atomization nozzle applicable to fire extinguishment of power transmission line mountain fire. The two-grade atomization nozzle comprises a nozzle shell, wherein the nozzle shell is internally provided with a nozzle inlet, a middle connection water path, a direct spraying water path, a primary spiral tapered cavity, a middle cavity and a secondary tapered cavity; the outlet of the primary spiral tapered cavity is communicated with the middle cavity; the middle cavity is communicated with the inlet of the secondary tapered cavity by a spiral water path; the outlet of the secondary tapered cavity is a water mist spraying opening; the middle part of the spiral water path is connected with an atomization inlet hole; and the nozzle shell is provided with a first valve mechanism which is used for controlling the nozzle inlet to be only communicated with the middle connection water path or be simultaneously communicated with the middle connection water path, and a second valve mechanism which is used for controlling the middle connection water path to be communicated or disconnected with the direct spraying water path and the water mist spraying opening respectively. The two-grade atomization nozzle has the advantages of simple structure, easiness for machining and manufacturing, low manufacturing cost, capability of rapidly converting to meet different working condition requirements and the like.