The main factor, which leads to semiconductor lasers degradation in space mission experiments, is the introduction of lattice defects in the detector material produced by radiation. Therefore, a new remaining useful life (RUL) prediction method considering radiation effect is presented. The prediction method is based on failure mechanisms and particle filters, which realizes the combination of a physical model and data-driven method. The particle filters can abundantly employ degradation data and avoid ignoring the failure mechanism. Accelerated degradation testing (ADT) is proposed for effectively assessing the proposed prediction method, in which the proton radiation is selected as the accelerated stress. The prediction results are compared with other methods to verify the accuracy and effectiveness of the proposed prediction method.