The invention relates to the technical field of paint product, in particular to diatom mud paint with visible light catalytic capability. The diatom mud paint is characterized in that nano g-C3N4 withthe visible light catalytic capability is taken as a photocatalyst which is added to a porous structure of the diatom mud paint, indoor visible light is used directly to degrade organic toxic substances adsorbed by diatom mud so that the diatom mud has better purification performance and durability, and toxic substance pollution such as indoor formaldehyde and toluene is reduced.