Excavation supporting method for tunnel construction

The invention discloses an excavation supporting method for tunnel construction. In the method, the tunnel is excavated in parts and blocks, arch part primary support and temporary steel frame support are erected to form reticular closed stable support system, and finally a complete tunnel section is formed, the excavation and support of each part are in vertical staggered manner along tunnel and are carried on through parallel advancing construction method. The excavation supporting method has large excavation part section, facilitates the operation of construction machinery, has simple primary-support process, easy operation, reduces the arch jack fabrication, anchor rod mounting and concrete spraying processes for middle partition and temporary inverted arch construction, reduces the construction period and the construction cost.