The total length of this section is 2.8 km, including subgrade, pavement, super major bridge and culvert etc. Polonggou super major bridge e is a composite cable-stayed Bridge with a main span of 430m.. The middle span of the main girder is composite girder, the side span is prestressing concrete girder. The span arrangement is （45+50+60+430+60+50+46）m.. This bridge has been recognized as the “First Bridge” of Tibet. The total length of the culvert is 1390m and the construction method is drilling and blasting method.