Elaborating the management of oilfield development is an inevitable course for the growing of CNPC overseas sector. With the low oil prices currently, it is more important than ever to have a set of evaluation method on oilfield development considering the characteristics of overseas oilfields. By means of combining Pearson Correlation Coefficient and Grey Relational Analysis together, the method of calculating weights has been improved. Based on the data of water-flooding sandstone reservoirs with medium to high permeability from CNPC's overseas development projects, the weights of nine indexes including the control degree of water flooding reserves have been decided. A typical oilfield has been analyzed by using fuzzy comprehensive evaluation method and the evaluation results are been analyzed from three perspectives. Membership functions are established to get the evaluation set of each index and the conclusions about the development performance of the oilfield are drawn from these evaluation sets. Then, the fuzzy comprehensive evaluation set can be worked out by fuzzy transforming with which the comprehensive evaluation results of the oilfield development performance can be obtained.