Spraying droplets into the cavity of the double skin façade can improve its thermal performance. However, the spray system is opened, the mist droplets (aerosols) dispersed in the cavity alter the transmission mechanism of solar radiation through the double skin façade. This study develops a solar radiation transfer model for double skin facade with spray aerosol based on the Mie scattering theory and the net radiation method. The model calculates the transmittance, reflectance, and absorptance of the double skin façade with spray aerosol. Experimental validation shows good agreement with the model, with a maximum error of approximately 11.2 % for solar heat gain. Additionally, this study examines key factors that influence the optical properties of the double skin facade with spray aerosol, including aerosol particle number concentration, average radius, cavity distance, and incidence angle. The results indicate that total transmittance decreases as aerosol concentration and average radius increase. However, when the concentration exceeds 600 particles/cm3 and the average radius exceeds 15 μm, the reduction in transmittance becomes less pronounced. Changes in cavity distance and incidence angle have a minimal effect on transmittance at high aerosol concentrations. By controlling aerosol concentration and average radius, solar heat gain can be effectively reduced. The model accurately describes solar radiation transmission in real conditions, helping assess the optical and thermal properties of double skin façades with spray aerosol.