Abstract: The sequence of geological age on Nideping terrace in Dongchuan, Yunnan Province was established by thermoluminescence. The result shows that the age of the terrace is 9.3-57.1 ka. The vertical age of ancient debris flow terraces was established, and the time structure of Nideping mud was received. The age data was provided for the restoration ancient environment of the debris flow. It is shown that the debris flow deposits have discontinuities through age data and exist age inversion. The radioactive elements such as uranium, thorium, potassium may be leaching deposition affected by the presence of local rainfall and the annual dose rate increases with depth.