This paper proposes a new extended polysilicon gate bulk silicon lateral insulated gate bipolar transistor (EGBS-LIGBT). In order to suppress the hole substrate current, N-type and P-type silicon are epitaxially grown on the P-substrate sequentially to serve as N-drift and P-drift. The PN junction composed of two drift regions is in a reverse-biased state during both normal conduction and off states of the device. The built-in potential within it forms a hole-blocking barrier to prevent holes from moving towards the substrate. Meanwhile, a Schottky-extended polysilicon gate (S-EG) is added on the P-drift, forming a thin electron-inversion layer on the inner surface of the P-drift, which can achieve a low on-state voltage (V_on). In addition, the Schottky contact at the anode reduces hole injection efficiency, while the rapid dynamic electric field modulation capability of P-drift enables the swift extraction of excess carriers stored in this region. The majority carriers in the P-drift being holes can also accelerate the recombination with the excess electrons during the turn-off phase. The above factors help to reduce the turn-off time and the turn-off energy loss (E_off). Simulation results show that EGBS-LIGBT effectively reduces the hole substrate current while improves the trade-off relationship between E_off and V_on. In this paper, EGBS-LIGBT has a V_on of 1.59 V, hole substrate current is 1.9 mA/cm², E_off is 0.51 mJ/cm², and breakdown voltage (BV) is 701V. Compared with conventional LIGBT, V_on is approximately equal, hole substrate current is reduced to 1/105 of it, E_off is reduced by 69.8%, and BV is improved by 19.6%.