The invention relates to a coal mine roadway construction technology, in particular to an ultra-high roadway supporting-before-digging tunneling method. The problem that the construction efficiency ofan ultra-high roadway is low is solved. According to the ultra-high roadway supporting-before-digging tunneling method, upward inclined blast holes are drilled in a rock stratum at an opening of a designed roadway, gunpowder is placed to explode coal on the upper portions of the rock stratum and a coal seam crisp, then a heading machine normally cuts the coal and conducts tunneling, then two rowsof blast holes are formed in the tunneling surface, the coal on the upper portions of the rock stratum and the coal seam are exploded crisp, the rock stratum is cut open by the two rows of blast holes, the upper portion of the rock stratum naturally falls to the bottom of the roadway, the heading machine normally cuts the coal and conducts tunneling, the lower portion of the coal seam is cut off,remaining rock and coal collapse, and the steps are repeated till the designed depth of the roadway is reached. Supporting construction is conducted while tunneling is conducted, and only one time oftop plate supporting is needed, so that the workload and the number of supporting materials in use are reduced, and the mining cost is greatly reduced. Therefore, the purpose of safely and rapidly forming the roadway at a time is achieved.