Head detection is a challenging and widely applied object detection task. Although previous CNN-based head detectors have made good progress, the inherent locality of CNN restricts the extraction of global contextual information, which leads to low precision and recall rates in head detection. In this article, we propose an end-to-end high-quality head detector based on Transformer, which effectively models the contextual relationships between heads, other objects and the background. To extract and generate discriminative feature maps suitable for detecting small head targets, we incorporate specific CNN-based auxiliary detector heads for joint training. The GIoU-aware classification loss function is improved to generate bounding boxes with high localization quality and high classification confidence, and a feature fusion module is introduced to enhance the feature representation capabilities of the model. We conduct experiments on COCO 2017 dataset and Brainwash head dataset, and the results demonstrate that our method outperforms in both COCO generalized object detection and Brainwash head detection tasks compared to previous CNN-based detectors as well as other current mainstream Transformer-based object detection models.