Aiming at the issue of violation of Pareto optimality in the preference aggregation of group decision, a method of homogeneous aggregation based on the geometric dispersion of group judgments is designed. In the method, a dispersion test is carried out to measure the dispersion level of group judgments, and the aggregation is explored based on the dispersion level. For the judgments with the lower dispersion level, it is proposed to combine the judgments with the geometric mean; for the judgments with the higher dispersion level, which are difficult to revise, the principal components analysis(PCA) is applied to capture the majority of the information associated with the original high dimensionality judgments from diversity of opinion, and combine the group judgments according to the weighted geometric mean without subjective analysis. The simulation experiments show that the proposed method can combine the group judgments with the biggish dispersion on the premise of the Pareto optimality principle.