In this paper we simulated thermal emission scale effect of plane non-isothermal surfaces

and validatedLi-Wang-Strahler's scale-corrected Planck law for non-isothermal surfaces; We used multivariate normal distribution togenerate component emissivity and component temperature under given the mean

variance and covariance ofcomponent emissivity and temperature. Given pixel temperature

two scale-corrected factors could be calculated.Comparing simulated scale-corrected factors with Li-Wang-Strahler's scale-corrected factors

we found the simulatedones always was close to the deduced. The simulation showed that Li-Wang-Strahler's model correctly redressed scaleeffect of non-isothermal surfaces.