Tunnel excavation device

The invention provides a device for pressing a cutter disc against a foundation while rotating the cutter disc so as to excavate the foundation, wherein the cutter disc is prevented from being damaged at a lowest cost. The tunnel excavation device is used for horizontally excavating a cylindrical or barrel-shaped tunnel in the foundation. The front end of the tunnel excavation device is provided with the cutter disc for excavating the foundation and capable of rotating around a central axis of the tunnel excavation device. The cutter disc comprises an excavation blade arranged on a planar front end surface, and a protruding part configured to protrude out of the front end surface. When the cutter disc is rotating, the protruding part is used for retaining the sand soil generated through excavating the foundation and covering the sand soil onto the front end surface.