Alveolar soft tissue sarcoma is a rare malignant tumor of soft tissue, more common in young women, with deep soft tissues in the limbs and buttocks being the most prevalent sites. There are few reported cases in clinical practice. The clinical manifestations lack specificity and the imaging signs are diverse. This case presents ultrasound, MRI and PET/CT images of alveolar soft tissue sarcoma of the gluteus maximus muscle to enhance readers’ understanding and awareness of the imaging signs of this rare disease in order to raise awareness of its diagnosis. The characteristics of this case are summarized and reported in combination with domestic literature.