Method for quickening construction of multiple-arch tunnel

The invention relates to a method for quickening construction of a multiple-arch tunnel. The method includes: firstly, pre-supporting a middle pilot tunnel; and secondly, excavating the middle pilot tunnel, constructing a left main tunnel, a right main tunnel, and a cover arch and a long pipe roof of the middle pilot tunnel, setting a widened segment allowing a loader to turn around in the middle of the middle pilot tunnel, and after the middle pilot tunnel is through, constructing a middle partition wall from an entrance of the middle pilot tunnel to an exit of the middle pilot tunnel. The method has the advantages that construction entering is assisted by advanced small pilot pipes so that entering construction period of the middle pilot tunnel is reduced; the section of the middle pilot tunnel is locally enlarged, the loader is used with a dumper for construction, and accordingly residue discharging efficiency is improved greatly; the construction method of the middle partition wall is modified, so that th