The abrasive block is one of the key factors affecting the quality and efficiency of barrel finishing process. The scientific evaluation index is an important premise for the rational evaluation of the abrasive blocks. Therefore, the construction of evaluation indices of the abrasive blocks based on the analytic hierarchy process (AHP) and principal component analysis (PCA) is proposed. Firstly, combining the actual cases of barrel finishing process and the preparation process of the abrasive blocks, the initial evaluation index is obtained by analyzing the selection principles of evaluation index. Secondly, the AHP and PCA are combined to screen the evaluation indexes and then build the final evaluation indices. Finally, according to the initial and final evaluation indices, the abrasive blocks are evaluated and the evaluation results are compared. The results show that the selection of evaluation indexes is reasonable and the evaluation index can be used to evaluate the abrasive blocks reasonably, so as to reduce the workload of collecting evaluation indices data and improve the evaluation efficiency of the abrasive blocks.