Abstract: To meet the requirement of the eight-year long life in-orbit data processing for the GF-3 satellite, an accelerated life test should be carried out to validate the reliability design of the onboard data processing unit (DPU). In this paper, a method based on the Arrhenius model is adopted to estimate the accelerating factor of the onboard DPU. The scheme design of the accelerated life test is described. The failure criteria are proposed with suggested measures, as well as the endurance criteria at the end of the lifetime. It is shown that all functions and performances of the DPU of the GF-3 satellite during and after the test meet the technical specifications. In a conclusion, the accelerated life test technology is an effective way to estimate the reliability of the onboard satellite products in a short time with a low cost, thus it can be widely applied in the design of aerospace electronic products in the future.