Aiming at intravitreal injection procedures for eye diseases, needless injectors are emerging to puncture complications, save time and improve the safety of the process. In this paper, an injection device based on electromagnetic E-core actuation is selected for its better position control and improved controllability over current solenoid designs. The multi-objective optimization model of the E-core device is derived. Then, an integrated NSGA-II and TOPSIS based on combinatorial weighting approach is proposed for the parameter optimization design of the device and the selection of a final compromise solution or optimal solution. The combination weighting method combines the advantages of the objective and subjective weighting method, making the results more reasonable.