To reduce the influence of the surface settlement and deformation of the buildings and the underground facilities caused by the subway station construction, that has a large flattened cross-section, it has to evaluate the contingent surface settlement and deformation correctly and help us to choose the better construction approach.

With the development of road tunnel construction and assorting with muti-lanes freeways, extra-large cross-section and low flat-ratio road tunnel become a new shape in recent years.

And based on the monitoring data in the entrance slope of the extra-large cross-section and cow flat-ratio tunnel,this paper applied the time series by the method for dealing with mutation to forecast the deformation of slopes.

In this paper,we treat the cavity of super-large section as the research subject and discuss the new technology of multilayer coupling construction method.

According to construction of Longtoushan two bores and eight lanes tunnel with super-large section and span in Guangzhou,the monitoring of surrounding rock deformation was carried out.