Facial overfilled syndrome (FOS), an iatrogenic complication in the field of minimally invasive injectable aesthetics, has been increasingly reported in recent years. It is traditionally considered to be simply caused by volume overload, and clinical interventions are mostly limited to volume-reduction strategies such as hyaluronic acid dissolution, which have limited efficacy for deep pathological changes including fibrous hyperplasia and restricted muscle function. This paper systematically reviews the pathological mechanism of FOS, the ultrasound imaging classification system and collagenase intervention strategies, so as to provide references for standardized clinical diagnosis and treatment.