Thin-top silicon-on-insulator (SOI) lateral insulated-gate bipolar transistors (LIGBTs) have a high forward saturation voltage drop. When a shorted collector structure is introduced to reduce the trailing current of the turning-off state, the forward saturation voltage drop increases further. A novel fast-switching LIGBT (F-IELIGBT) device based on injection enhancement (IE) is proposed in this study, and its working mechanism is theoretically analyzed and verified through a simulation. The F-IE-LIGBT device is built on a thin-top SOI substrate, and its collector is designed using injection-enhanced and potential control structures. Combined simulation results show that the F-IE-LIGBT device can obtain a smaller forward saturation voltage drop, reduce the trailing current of the turning-off state, and achieve a fast turn-off characteristic. The F-IE-LIGBT device is highly suitable for SOI-based high-voltage power integrated circuits