Objective To investigate the relationship of autophagy and cell death in CT26, a cell line from mouse colon cancer was used and treated by triptolide. Methods Immunofluorescence staining, LC3 adenovirus vector (mRFP-GFP-LC3), and Western blotting methods were adopted to examine autophagy flux in CT26 cells. The AQueous one solution cell proliferation assay(MTS) and AnnexinV-FITC/PI reagents were used to evaluate the cells inhibitions rate, apoptosis and cell death rate of CT26 cells after treated by triptolide, rapamycin, and triptolide combined with rapamycin. Results The CT26 cells showed significant autophagy flux induced by triptolide and activating cell autophagy improved the late CT26 cell apoptosis rate. Compared with the group of triptolide, the group of triptolide combined with rapamycin obviously increased CT26 cell death. Conclusion Triptolide promotes colon cancer CT26 cell death through induction of autophagy.