Total dose irradiation effect and reliability of domestic partially-depleted SOI MOSFET were studied. It is found that the oxide-trapped charge mainly causes the threshold voltage shift. The back gate is more sensitive to the total dose irradiation than the top gate, while it is still the top gate that determines the radiation performance of the device as the back gate shifts within a certain scope. The descendent of the saturated current results from the action of the interface-trap charge. It is also believed that the total dose irradiation will lower the device reliability.