In order to investigate the effects of Litsea cubeba essential oil （LCEO） on the proliferation and apoptosis of Spodoptera litura （SL） cells cultured in vitro and preliminarily determine the main toxic activity component，the CCK，MTT assay and flow cytometry were used to study the inhibitory effects of different concentrations of LCEO on SL cells. The effect of different concentrations of citral on the apoptosis of SL cells was verified by flow cell method. The results showed LCEO can inhibit the proliferation of SL cells，and with the increase of the concentration of LCEO and the prolongation of treatment time，the survival rate of SL cells decreased. When the concentration of LCEO was increased to 0.015%，the survival rate of SL cells was significantly lower （P<0.01）. And the treatment time reached 72 h，the survival rate of SL cells decreased significantly. As the main active component of LCEO，citral has obvious inhibitory effect on SL cells，and the dose is positively correlated. In addition，the citral concentration was greater than 0.015%，the survival rate of SL cells was significantly decreased （P<0.01）. It is indicated that LCEO and citral can effectively promote cell apoptosis and show dose dependence，and citral is the main active ingredient of LCEO to promote apoptosis of SL cells. So，it also provides a basis for the development and utilization of new plant-derived pesticides based on LCEO.