To obtain a more objective and scientific result of power quality（PQ） fuzzy synthetic evaluation， this paper presents a combined weighing method to determine weights of PQ indices. The new method integrates advantages of both objective weighing and subjective weighing and remedies the defects of single-weighing. For more applications， a sequence synthesis-G1 technique is also put forward to evaluate PQ levels of the point of common coupling（PCC）. Calculated results show that the proposed method with more objective and sufficient weights of PQ indices leads to a more scientific and accurate evaluation.