This work numerically studies the evaporation process in thin liquid film of a sessile binary droplet on heated solid substrates using a comprehensive model, with a self-rewetting binary droplet - 5wt% aqueous n-butanol solution as working fluid. The effects of substrate thickness and thermal properties on the heat transfer characteristics of the evaporating thin film in the sessile droplet are investigated. A temperature valley value exists in the thin film on the substrate surface, corresponding to a peak value of heat flow rate. Increasing solid substrates thickness tends to increase the length of conduction path and decrease interfacial temperature. The maximum mass flow descends and shifts to the position at lower disjoining pressure where the liquid thin film is thicker. The thin film length of the nonmetal materials substrate is obviously longer than that of the metal substrate for the better wettability. The maximum mass flux exists at the thin film region and increases with increasing thermal conductivity. The contribution of the thin film region to the overall heat transfer increases significantly with decreasing thermal conductivity of the solid substrate. Meanwhile, the thin film contribution is relatively less sensitive to the substrate thickness than the thermal properties.