Regarding the complexity of the judgment for power system planning alternatives and the fact that analytic hierarchy process (AHP) has the strong subjective and data envelopment analysis (DEA) can not reflect the preference of decision makers, a method integrating AHP and DEA is proposed. The method is divided into two models whether grey relational method is fused. Meanwhile, two models are applied to a practical power system planning problem by establishing an evaluation system for power planning. It is showed that the calculation result is consistent with the expected result. On the basis, the fault-tolerant for the models is analyzed. It is found that the fault-tolerant of the model with the grey relational method is better than other methods. When the abnormal factors affect power system planning, the model with the grey relational method can still choose the optimal plan.