Because electromechanical brake (abbr. EMB) can be integrated with ABS/ESP/ACC very easily and adaptive cruise control (abbr. ACC) requires the car with the function of active brake, the primary research of ACC based on EMB was given. For this purpose，the out-line simulation platform including mathematical models for engine, EMB, vehicle，ACC arithmetic and virtual scene has been built and the simulation on two typical follow conditions was given. The results showed that the ACC based on EMB could control the velocity of ACC vehicle and the headway of cars effectively and the virtual scene could show the change for headway of cars and velocity of vehicles intuitively, so it is helpful for us to optimize control algorithm.