Abstract: The soft clay of plateau slope formed under specific climatic and geologic environment and with peculiar properties is an unusual geologic phenomenon.The problem of the stability of embankment will confront us when highway or railway is constructed on the soft clay.By research of construction test of the slope embankment in Laoguochang-Lizigou of the Neijiang-Kunming railway line, the measure of "strengthening foundation and body" and "consolidating soft clay and preventing landslide" is presented to ensure the stability of embankment.The conclusion has referential value to the similar project.