In order to conduct a rapid assessment of product life, the effectiveness and applicability for life prediction based on reliability simulation method was discussed. Taking a vehicle-carried processor as research object, the weaknesses of thermal design and vibration design were exposed and the average life of 4.84 years was predicted. Compared to the reliability prediction method, this method doesn’t rely on the failure rate in the handbook and has high precision. Compared to the accelerated life test method, this method has lower cost and test time, which has a bright application prospect.