Taking as a newly-proposed drive control technology, the piezoelectric injection technology provides a reliable approach for the precise injection of tiny fuel and multi-injection due to its rapid and dynamic response. A onedimensional electricalmechanicalhydraulic coupling mathematical model of selfdeveloped piezoelectric injector was established based on AMESim software. Taking the response characteristic index of injector needle valve as the optimized object, the structural parameters that had a great influence on the response characteristic of injector were determined. The orthogonal experimental optimization (DOE) and genetic algorithm were used respectively so that multiobjective optimization of key structural parameters was carried out. The results show that the opening delay and duration of needle valve shorten by 16% and 23.6% respectively and the closing delay and duration shorten by 13.6% and 13.3% respectively after optimization. The response characteristics of needle valve greatly improve, which is conducive to realize tiny fuel injection and multi-injection.
