Abstract: According to the elements of evaluation test for life of nuclear cables, and based on the characteristics of polymer materials commonly used in nuclear power cable, such as XLPE and low smoke zero halogen XLPE, A test for the evaluation of safe service life of nuclear cables was designed and conducted for about 5 000 hours. At the same time, Least Square method, which is more accurate in the mathematical statistics, was used to deal with the test data. This overcame the inaccurate defect of evaluating the life of cables with accelerated aging method for electrical properties. The final test results indicate that the cable can meet the requirement of service for sixty years. This study is of actual importance for the design and operation of nuclear cable.