针对传统地下开采矿山岩体质量评价指标之间存在信息冗余的问题，以国内某海下开采金属矿山为例，选用岩石单轴饱和抗压强度、岩体质量指标RQD值、结构面状况等8个指标作为评价指标,采用主成分分析法对评价指标进行降维处理，获得方差累积贡献率达94.873 %的前2个主成分，根据单指标分类区间构造5个岩体质量等级，建立岩体质量评价的EWM-TOPSIS评价模型。研究结果表明：相对传统的可拓评价方法，PCA-EWM-TOPSIS耦合算法对岩体质量分级结果的准确率达88.2 %，评价结果与可拓评价方法评价结果基本一致，且PCA-EWM-TOPSIS耦合算法解决了评价指标过度冗余的问题，大大简化了计算过程，提高了岩体质量评价的效率。该方法具有良好的工程应用价值，可以应用于地下开采矿山岩体质量分级中。

In view of the problem of information redundancy between traditional quality evaluation indicators of underground rock mass,8 indicators,such as the uniaxial saturated compressive strength of rocks,the RQD value of quality indicators of rock mass,and the status of structural planes,are selected as evaluation indicators for an undersea metal mine in China.The first 2 principal components with a variance cumulative contribution rate of 94.873 % are obtained by dimensionality reduction of the evaluation indexes using principal component analysis (PCA),and 5 rock mass quality grades are constructed based on the single index classification interval to build an EWM-TOPSIS evaluation model for rock mass quality evaluation.The results of the study show that the PCA-EWM-TOPSIS coupled method achieves 88.2 % accuracy for the quality grading results of rock mass with respect to the traditional topological assessment method,and the evaluation results basically agree with the evaluation results of the topological assessment method,and the PCA-EWM-TOPSIS coupled method solves the problem of the over-redundancy of the evaluation indexes,greatly simplifying the calculation process and improves the efficiency of the quality evaluation of rock mass.The method has good engineering application potentials and can be applied to underground rock mass quality grading.