This paper aims to prepare a fluorescent composite coating with high afterglow brightness and long afterglow time. The main luminescent material of the coating is SrAl2O4:Eu2+,Dy3+, and SiO2 is coated on its surface by sol-gel method. The main film-forming material is industrial grade water-based silicone acrylic emulsion. By adding appropriate amount of glass flakes, the mechanical properties of the coating could be greatly increased to improve the application performance of the coating without much influence on the afterglow effect of the coating. The afterglow brightness and time of the fluorescent coating were increased by the aluminum power bottom coating. By measuring the afterglow brightness, after glow time, reflectivity and drawing adhesion and other related properties, the experimental optimization of fluorescent coating composition ratio, the afterglow brightness is 4.227 cd/m2 and the afterglow time is 1471.6 min (24.5 h) at the fluorescent coating thickness of 550 μm. The reflectivity of the aluminum powder coating prepared by choosing the appropriate particle size of the flake aluminum powder can reach more than 64%, and the afterglow brightness increases to 5.998 cd/m2 after adding the reflective layer, which is about 40% more than that of the single fluorescent coating; the afterglow time increases to 1855 min (30.9 h), which is about 26% more than that of the single fluorescent coating. In a certain range, the afterglow brightness and afterglow time of the fluorescent composite coating are greatly affected by the amount of phosphor added and the thickness of the coating, but the increase of afterglow brightness tends to be gentle after reaching a certain content. It is an effective technical way to improve the luminance and duration of fluorescent coating by adding matching aluminum powder coating.