Abstract: Adding non-cationic surfactant in water can effectively enhance the wettability of water on coal surface, and the wettability of coal surface is affected by the type of solution and the physical and chemical properties of coal surface. In order to study the influence of the roughness of the surface wettability of coal, five types of coal with different surface roughness and 5 non-cationic surfactants, SJ-210 surface roughness measuring instrument, JC2000D dynamic contact angle measuring instrument and other equipment were used for experiments, the surface energy of briquette wetted by each solution was calculated. The results show that the briquette surface roughness is in the range of 0.5 μm to 5 μm. The contact angle formed by non-cationic surfactant solution on briquette surface is negatively correlated with the briquette surface roughness, and the briquette surface energy is positively correlated with the briquette surface roughness; when the mass fraction of non-cationic surfactant is 0.01%, the surfaceroughness of briquette has the greatest influence on the wettability of fatty alcohol polyoxyethylene ether; when the mass fraction is 0.05%, it has the greatest influence on decyl glucoside; when the mass fraction is 0.10%, it has the greatest influence on sodium dodecyl sulfate; when the mass fraction is 0.20%, the surface roughness of briquette has the greatest influence on the wettability of fatty alcohol polyoxyethylene ether. When the mass fraction was 0.40%, it had the greatest influence on decyl glucoside; the wettability of surfactant with lower mass fraction is more affected by briquette surface roughness. It is of great significance to control briquette surface roughness by using low-concentration surfactant solution to conduct briquette wettability experiment in laboratory.