In order to improve the scientific nature of index weighting in radar equipment reliability evaluation， in view of the problem of subjective weighting method relies too much on individual experience， and objective weighting method collects less data， resulting in inaccurate objective weighting results， the improved analytic hierarchy process （AHP） and entropy weight method are used to assign the indexes to the subjective and objective weights respectively. The least square method is used to couple the subjective and objective weights， and the Lagrange method is used to solve the model， which effectively avoids the limitation of single weight. The feasibility of the method is verified by an example.