Atmospheric aerosol scattering phase function (ASPF) is vital for studying aerosol radiative forcing in the Earth-atmosphere system. Currently, most ASPF measurements still rely on simulations or indirect retrievals due to limited direct measurement instruments. This study presents a novel automated rotational detection system that directly measures ASPF from 5° to 357°, using lasers at 355 nm, 532 nm, and 1064 nm. Multiple photodetectors rotate around a cylindrical scattering chamber to capture scattering intensity at 36 angles. By comparing Mie theory with measurements, system performance is validated with polystyrene latex (PSL) and free-floating aerosols. This multi-wavelength, multi-angle, high-precision system holds scientific significance for aerosol scattering and climate effect studies.