The utility model discloses an instrument of regional cubic metre of earth of machine excavation tunnel steel bow member is dug in cooperation, it includes: a bucket to and an at least detachably installs the blade on the bucket, the utility model discloses the device is applicable to weak soil layer of tunnel excavation and severely -weathered country rock. Solved and dug the not enough of the operating space of machine own, increased the excavation ability of digging the machine.