A Density Peaks Clustering algorithm based on optimized AdaBoost-DPC is proposed to deal with the class-imbalanced question of target and clutter in radar data sets. The method of density peaks clustering is introduced, and the clutter dots are under-sampled. The error function of AdaBoost algorithm is improved based on the asymmetric misclustering cost, which raises the weight of positive misclassification cost. Then the improved AdaBoost algorithm is combined with density peaks clustering method to cluster the imbalanced radar data sets consisting of the targets and clutter dots. The experimental results show that the optimized method can effectively improve the identification of target.