During the growth and development from childhood to adolescence, long-term nail-biting behavior can cause multisystem damage. In terms of appearance, it leads to rough nail plates, nail bed deformity, and periungual skin damage, which is susceptible to secondary infections such as paronychia and verruca vulgaris. In the oral cavity, it can induce developmental abnormalities including malocclusion and temporomandibular dysfunction. Meanwhile, the increase of Enterobacteriaceae within the oral microflora may raise the risk of diarrhea. In adulthood, repeated nail-biting may interfere with the clinical diagnosis of clubbed ffngers, and accidental ingestion of nail fragments can cause lesions such as granulomatous gastritis. This paper systematically reviews the research progress and treatment strategies of nail-biting behavior, aiming to provide theoretical references for subsequent clinical intervention and in-depth research.