The pepper essential oil was extracted through steam distillation, and the chemical composition of the essential oil was assessed via GC-MS. The fumigation effect of different amounts of dried mushrooms and exposure time of the pepper oil against tribolium castaneum egg was studied. The results show that the extraction rate of the pepper oil is 7.2%, which is relatively higher. The chemical composition of the oil mainly contains linalool (relative content 68.46% )、limonene (relative content 7.53%)、b-terpinene (relative content 4.13%), et al. When filled with different weights of dried mushrooms(0,5,10,15,30 g), the cL50 of 24h fumigation are respectively 34.83, 36.84, 40.34, 52.48 and 117.35 μL/L. The cL50 of 48 h fumigation are respectively 29.28, 32.72, 33.21, 35.42 and 77.63 μL/L. The cL50 of 72 h fumigation are respectively 20.29, 21.35, 22.55, 25.63 and 51.12 μL/L. As dried mushrooms filling volume increases, the fumigation effect against tribolium castaneum egg reduces. The method of extending the exposure time can also improve the fumigation effect of pepper essential oil and achieve a better insecticidal effect.