The interfacial thermal resistance between two solid materials is usually obvious in thermal management technology, but there is still no way to eliminate it nor uniform measurement standard. When taking thermal measurements because the surface roughness of instrument probe and device package directly affects the interface morphology, the change of total thermal resistance caused by the thermal contact resistance (TCR) fluctuations disturbs the accuracy of internal thermal analysis of device. We prepared samples with different surface roughness and performed thermal measurements on them, compared with test under vacuum environment and the condition filled with thermal interface materials, respectively. We found the heat-transfer mechanism of interface. More importantly, it is shown that in the interval of surface roughness [Formula: see text], the TCR shows good consistency when filled with thermal interface materials. This result will help to improve the convenience of measurement for the accuracy of thermal measurement technology.