Large-torque spiral drilling tool

The utility model relates to the technical field of drilling tool structures, in particular to a novel spiral drilling tool which can achieve the large-diameter rotary excavating function, expand the use working condition range of a drilling rod and prolong the service life of the drilling rod, and particularly relates to a large-torque spiral drilling tool which comprises a spiral drilling rod. The tail end of the spiral drill rod is connected with the connector unit at the corresponding position through a connecting mechanism, the connector unit is connected with the connecting base at the corresponding position, an alloy drill bit is installed at the front end of the spiral drill rod, and spiral blades are fixedly welded to the outer side wall of the front portion of the spiral drill rod along the circumference of the spiral drill rod. And the tail end of the connecting seat is used for being connected with an upstream driving unit. When the large-torque spiral drilling tool is used for drilling, large-dia