Tunnel face drilling mechanism with underneath type drilling machine and construction method of tunnel face drilling mechanism

The invention relates to the technical field of underground engineering, in particular to a tunnel face drilling mechanism with an underneath type drilling machine and a construction method of the tunnel face drilling mechanism. The sliding pedestal is arranged on the propelling beam and can move relative to the length direction of the propelling beam; a rock drilling machine and a transmission box are arranged on the sliding pedestal at intervals, the rock drilling machine and the transmission rod are located below the propelling beam, the first drill rod is located above the propelling beam, the transmission box is connected with the transmission rod and the first drill rod, the rock drilling machine can drive the transmission rod to rotate, and the transmission rod can drive the first drill rod to rotate through the transmission box. The rock drilling machine is arranged below the propelling beam, the propelling beam can be closer to the primary support so as to reduce the outer inserting angle during dril