The paper researched the insecticidal activity of the extract from the puparium of Monema flavescens Walker to provide the basis for developing new biogenic pesticides and exploring the application prospects in the prevention and control of garden pests. The results showed that the active ingredient HC263 of the puparium extract had a control effect of more than 90% against the Aphis salicifera at a dosage of 100 mg/kg. The lethal concentration in 24 hours was 64.7688 mg/kg, which had an excellent control effect.