This paper investigates the control strategy of engine smart start/stop system, and develops the simulation model of the micro car equipped with smart start/stop system in Matlab/Simulink environment. The schematic and the starting process dynamics of the engine smart start/stop system are analyzed. The simulation results of the fuel economy between the baseline vehicle and the vehicle after installation of smart start/stop system are discussed using Matlab and ADVISOR software co-simulation in the NEDC driving cycle. Finally the test of engine start and the emissions test of the micro car equipped with smart start/stop system are conducted using standard chassis dynamometer. The results indicate that the engine of the micro car can be automatically shut off as it meets the conditions of engine automatic stop. The 100-kilometer fuel consumption of the micro car equipped with start/stop system decreases by 3.63% compared to that of the baseline vehicle, and the test result of the fuel saving ratio is consistent with the simulation result. The HC, CO and NOx emission results of the micro car equipped with smart Start/Stop system are 0.047 g/km, 0.542 g/km and 0.035 g/km, respectively. And the emissions are much lower than those of the Euro - emission limits.