This paper reports a case of acute severe dichlorvos poisoning complicated with nosocomial nasal myiasis. During the treatment process of the primary disease, patient’s nasal cavity was found to be infected with fly maggots. Nasal irrigation was performed for isolation and prevention, along with local application of antimicrobial agents, no further maggots were found afterwards. Due to massive gastrointestinal bleeding, the patient ultimately ceased treatment and was discharged, and died on the day of follow-up. This paper combines literature review to analyze the infection characteristics, regional distribution, clinical characteristics, and treatment strategies of myiasis, aiming to provide reference basis for formulating effective prevention, diagnosis, and treatment measures.