In this paper, the experimental investigation on the electrical properties of silicon-on-insulator lateral insulated gate bipolar transistor (SOI-LIGBT) after total-ionizing-dose (TID) irradiation is presented. We find that the TID irradiation reduces the threshold voltage (V-th), and increases the collector current (I-CE) at the same gate voltage (V-g). The raising I-CE is mainly attributed to the negative shift of the Vth. However, at the same overdrive voltage (V-ov = V-g - V-th), the I-CE at small V-CE increases and the I-CE at high V-CE decreases after irradiation. The distinctive response of the out-put characteristics after irradiation is ascribed to the positive trapped charges in the field oxide (FOX) layer and the buried oxide (BOX) layer. The inimitable out-put behavior occurs at whatever the sign of the gate bias voltage during irradiation. The degradation mechanisms of the TID effects on the SOI-LIGBT are further analyzed and confirmed by simulation.