Disclosed herein is a method for predicting a reliable lifetime of a SOI MOSFET device. The method comprises: measuring a relationship of a gate resistance of the SOI MOSFET device varying as a function of a temperature at different wafer temperatures; performing a lifetime accelerating test on the SOI MOSFET device at different wafer temperatures, so as to obtain a degenerating relationship of a parameter representing the lifetime of the device as a function of stress time, and obtain a lifetime in the presence of self-heating when the parameter degenerates to 10%; performing a self-heating correction on the measured lifetime of the device by using the measured self-heating temperature and an Arrhenius model, so as to obtain a lifetime without self-heating influence; performing a self-heating correction on a variation of the drain current caused by self-heating; performing a self-heating correction on an impact ionization rate caused by hot carriers; and predicting the lifetime of the SOI MOSFET device under a bias. The embodiment of the invention prevents the self-heating effect from affecting the SOI MOSFET device in a practical logic circuit or in an AC analog circuit, which leads to a more precise prediction result.