The RC-IGBT(reverse conducting insulated gate bipolar transistor) is a new kind of power semiconductor device which has many advantages such as smaller chip size,higher power density,lower manufacturing cost,softer turn off behavior,and better reliability.However,its performance has a number of drawbacks,such as the snap-back effect.In this paper,an introduction about the snap-back effect of the RC-IGBT is given firstly. Then the physical explanations are presented with two simplified models.After that,some numerical simulations are carried out to verify the correctness of the models. The RC-IGBT (reverse conducting insulated gate bipolar transistor) is a new kind of power semiconductor device which has many advantages such as smaller chip size, higher power density, lower manufacturing cost, softer turn off behavior, and better reliability. Home, its performance has a number of drawbacks, such as the snap-back effect.In this paper, an introduction about the snap-back effect of the RC-IGBT is given first. Then the physical explanations are presented with two simplified models. After that, some numerical simulations are carried out to verify the correctness of the models.