Dry jet mixing pile(DJM pile) is a method of the soft soil foundation treatment in strengthening treatment of soft soil Highway's roadbed,such as silt,mud silt,clay,silty soil,and so on.Those calculation methods of the pile-soil stress ratio and the bearing capacity of composite foundation were analyzed by according to the characteristic of bearing capacity and settlement for DJM pile composite foundation on Highway's Roadbed and bridge head embankment of highway.The results are significant for taking account of the effects of pile and soil in the design of the DJM pile composite foundation of highway's roadbed and bridge head embankment of highway.