Abstract: Based on a high-speed gasoline engine, the combustion chamber structure, fuel injection characteristics and cam profile are redesigned as a lean burn engine. A research method of timing strategy analysis and optimization using response surface model is proposed and the process of multi-objective optimization calculation by using response surface is established. To improve the effective power and reduce the effective fuel consumption rate, the engine performance and response surface coupling optimization model is established by taking ignition timing, air-fuel ratio and intake and exhaust timing as design variables. The analysis and test results show that compared with standard mixture ratio combustion, with reduced inlet and exhaust advance angle and advanced ignition timing, the minimum fuel consumption of the lean-burn engine is reduced by 3.9% and the maximum power is increased by 9.7%; at the same time, the method of response surface optimization improves the optimization efficiency

Key words: lean burn, timing strategy, response surface method, multi-objective optimization, experimental verification