A method for optimizing a rotation angle of an outlet of an atomizing nozzle, the atomizing nozzle comprising a nozzle core and a nozzle body, characterized in that the method comprises the following steps: measuring an outlet flow rate Q 0 of the atomizing nozzle under a rated working pressure H when an outlet clearance between the nozzle core and the nozzle body is δ =0; setting the outlet clearance between the nozzle core and the nozzle body to δ by changing a phase angle α between the nozzle core and the nozzle body, constraining a position of the nozzle core, and measuring an outlet flow rate Q 1 of the atomizing nozzle in a stable working state under the rated working pressure H; an area of the outlet of the atomizing nozzle is S 1 = π × A × δ, wherein A is an inner diameter of the nozzle body or an outer diameter of the nozzle core; calculating a flow coefficient μ of the atomizing nozzle based on the following formula: Q 1 − Q 0 = S 1 − S 0 × v = π × A × δ × μ × 2 gH, wherein: v is an outlet flow velocity of the atomizing nozzle, and v = μ 2 gH; S 0 is the area of the outlet of the atomizing nozzle when the outlet clearance is δ =0, and S 0 =0; μ is the flow coefficient of the atomizing nozzle, and μ = Q 1 − Q 0 / π × A × δ × 2 gH; calculating the outlet clearance δ 2 of the atomizing nozzle according to an expected outlet flow rate Q 2 of the atomizing nozzle and the flow coefficient μ of the atomizing nozzle, wherein δ 2 = Q 2 − Q 0 / πAμ 2 gH; and according to an assembly relationship between the nozzle core and the nozzle body, setting the outlet clearance between the nozzle core and the nozzle body to δ 2 by changing the phase angle between the nozzle core and the nozzle body to α 2. measuring an outlet flow rate Q 0 of the atomizing nozzle under a rated working pressure H when an outlet clearance between the nozzle core and the nozzle body is δ =0; setting the outlet clearance between the nozzle core and the nozzle body to δ by changing a phase angle α between the nozzle core and the nozzle body, constraining a position of the nozzle core, and measuring an outlet flow rate Q 1 of the atomizing nozzle in a stable working state under the rated working pressure H; an area of the outlet of the atomizing nozzle is S 1 = π × A × δ, wherein A is an inner diameter of the nozzle body or an outer diameter of the nozzle core; calculating a flow coefficient μ of the atomizing nozzle based on the following formula: Q 1 − Q 0 = S 1 − S 0 × v = π × A × δ × μ × 2 gH, wherein: v is an outlet flow velocity of the atomizing nozzle, and v = μ 2 gH; S 0 is the area of the outlet of the atomizing nozzle when the outlet clearance is δ =0, and S 0 =0; μ is the flow coefficient of the atomizing nozzle, and μ = Q 1 − Q 0 / π × A × δ × 2 gH; calculating the outlet clearance δ 2 of the atomizing nozzle according to an expected outlet flow rate Q 2 of the atomizing nozzle and the flow coefficient μ of the atomizing nozzle, wherein δ 2 = Q 2 − Q 0 / πAμ 2 gH; and according to an assembly relationship between the nozzle core and the nozzle body, setting the outlet clearance between the nozzle core and the nozzle body to δ 2 by changing the phase angle between the nozzle core and the nozzle body to α 2. v is an outlet flow velocity of the atomizing nozzle, and v = μ 2 gH; S 0 is the area of the outlet of the atomizing nozzle when the outlet clearance is δ =0, and S 0 =0; μ is the flow coefficient of the atomizing nozzle, and μ = Q 1 − Q 0 / π × A × δ × 2 gH; calculating the outlet clearance δ 2 of the atomizing nozzle according to an expected outlet flow rate Q 2 of the atomizing nozzle and the flow coefficient μ of the atomizing nozzle, wherein δ 2 = Q 2 − Q 0 / πAμ 2 gH; and according to an assembly relationship between the nozzle core and the nozzle body, setting the outlet clearance between the nozzle core and the nozzle body to δ 2 by changing the phase angle between the nozzle core and the nozzle body to α 2.