Objective of this study was to explore effect of Methomyl on apoptosis of Musca domestica embryonic cell line（MDEC-07114）. Experimental groups were the different concentrations of Methomyl groups（1mg/ml, 2mg/ml, 4mg/ml and 8mg/ml）, normal group and 1% acetone group. The morphology of apoptosis cells was observed by hematoxylin-eosin staining, and the apoptosis index（AI） was measured. The apoptosis of MDEC-07114 cell was detected by TUNEL. Results showed that from the 2mg/ml groups of Methomyl, the typical apoptotic cell began to appear. Moreover, with the increase of the concentration, the apoptosis index（AI） gradually increased. TUNEL assay showed that at the 2mg/ml groups, MDEC-07114 cells appeared visible green fluorescence, the green fluorescence in cells enhanced at the 4mg/ml groups, and it was the strongest at the 8mg/ml groups. Conclusion of this experiment was methomyl could induce apoptosis of MDEC-07114 cells.