To improve mechanical efficiency, the tribological performance of short period intermittent motion needs to be investigated. Based on the theory of thermal elastohydrodynamic lubrication (EHL) and considering the influences of rough surface, a mixed-EHL model under point contact simple sliding intermittent motion is established. Using this model, the transition from mixed-EHL to EHL in the contact area is realized by changing the period of intermittent motion and setting the surface roughness. It is found that the thermal effect in simple sliding intermittent motion should not be ignored, and the pressure, temperature rise distribution and friction coefficient during the stop and start-up are fluctuated obviously. Under the condition of rough surface contact, the contact area will enter the mixed-EHL state during the stop and start-up. Shortening the period of intermittent motion is beneficial to alleviate the adverse effect of the mixed-EHL.