Abstract: The key structural parameters of the electronic controlled injector make a notable impact on the response time of the injector. This paper uses the non-dominated sorting genetic algorithm-Ⅱ(NSGA-Ⅱ) method to optimize the parameters of the injector. The optimization is based on the multi-objective optimization platform, modeFRONTIER, and utilizes the hydraulic simulation software AMESim. Aiming at the delay functions of the opening and closing of the nozzle, the multi-objective optimization model is established and the optimization design of injectors key structural parameters is implemented. The results show that the delay of the nozzle opening is 0.25ms, which is reduced by 16.7%; while the delay of the closing is 0.78ms, which is reduced by 15.2%.