This paper investigated the asymptotic stability and string stability problem for autonomous platoon control systems. The stability of the platoon system was analysed with the presence of engine constant uncertainty and time-varying transmission delay. An event-triggered based control method is presented，which can realized asymptotically stable of the autonomous platoon system. Based on this control strategy, additional restrictive conditions are derived for the string stable based on Z-transform. The effectiveness and advantage of the presented methodology are demonstrated by experiments with Arduino cars designed by Atmega2560.