This paper presents the results of an experimental investigation for the effect of radiant heat on the evaporation cooling of water droplet in the process of fire extinguishing. The experiments are mainly focused on the surface temperature, the surface roughness and the droplet diameter. The range of surface temperature is T$_{s}$ =80－14$0^{circ}C$, surface roughness is R$_{a}$=0.08－0.64 ${mu}{ extrm}{m}$ and the droplet diameter is $Phi$=3.0 mm in the radiation. The results show that the evaporation time is shorter for the larger surface roughness and the volume of droplet increased when the surface roughness is 0.64 ${mu}{ extrm}{m}$ at the surface temperature 127$^{circ}C$. When the surface roughness is 0.64 ${mu}{ extrm}{m}$, the heat flux is larger than the surface roughness is 0.08 ${mu}{ extrm}{m}$ at the surface temperature 81$^{circ}C$.>.>.