Research conclusions: For construction of the large section IV and Ⅴgrades weak surrounding rock tunnel of the Guiyang － Guangzhou Railway，based on summing up the experience of the traditional three － bench construction method，the three － bench and six short － range method was used in construction to divide the excavation section into three benches and six working faces with synchro － construction on the upper，middle and low benches． With this method，the deficiencies of lots of procedures，long construction period，insufficient turbulence on the surrounding rock in using CRD method and twine sidewall method can be overcome and the construction period can be shortened by machinery construction． The construction practice shows using this method can guarantee the construction security and enhance the construction process．