To optimize the trade-off relationship between EMI and Eonfor the floating P-base IGBT structure, a floating P-base IGBT structure with a dummy gate trench connected to a poly barrier layer was proposed. Two symmetrical dummy gate trenches were introduced in the floating P-base of the new structure, which were connected to each other by polysilicon. The dummy gate trenches divided the floating P-base into three parts, which decreased the number of holes accumulated near the gate trench and the inherent gate displacement current. The simulation results of the two-dimensional structure show that, compared with conventional IGBT, the proposed structure’s hole current density near the gate trench is reduces by 90% at low turn-on current. This reduction significantly reduces the peak values of collector current overshoot (ICE) and gate voltage overshoot (VGE), thereby improving the control capability of the gate resistance at dICE/dt and dVKA/dt. For the same turn-on loss, the maximum values of dICE/dt, dVCE/dt and dVKA/dt in the new structure are reduced by 32.22%, 38.41% and 12.92% respectively, thus reducing EMI noise and improving the trade-off between EMI noise and turn-on loss of the device.