Spray-wall impingement is a widely observed phenomenon in modern internal combustion engines. The formation and evaporation of the wall film significantly impacts the fuel-air formation as well as combustion and exhaust pollutants. In this study, fuel film evaporation experiments were carried out under a constant wall temperature condition for n-decane, n-dodecane, and their blends in order to gain a better knowledge of film evaporation characteristics. Moreover, the effects of wall temperature and mass ratio of mixed fuels on wall film thickness, area, volume, and lifespan were investigated. Furthermore, it was found an unexpected phenomenon in which the lifetime of the bi-component fuel film might be shorter than that of the pure n-decane fuel film under certain operating conditions. Finally, the processed data provided solid data to validate the unsteady one-dimensional analytical models.