Few-shot learning consists in training a classifier, which can be quickly adapted to new tasks with a few samples. To address the few-shot learning tasks, metric-based meta-learning methods explore the appropriate metrices to measure the similarity between the support and the query samples. However, existing methods ignore the similarity relationship between the labeled samples in the support set. Consequently, we propose a contrastive knowledge-augmented self-distillation approach to leverage the similarity relationship between a few labeled samples in the support set and allow the model to focus on more regions of images. Specifically, we calculate the classification probability of query images and each class prototype, respectively, and consider the classification probability of each class prototype as the teacher to guide the classification of query samples. Meanwhile, we design a contrast loss to bring the eigenvectors of the same class closer and push the eigenvectors of different classes further. In addition, a transformation function is implemented to allow the model to focus on more regions of the images, so as to obtain the key features. Extensive experiments are conducted on miniImageNet, tieredImageNet, and Caltech-UCSD birds 200, and the results show that our method can enhance metric-based meta-learning methods and outperforms the state-of-the-art methods.