The invention discloses an anchor rope total length anchoring method for a coal mine soft rock roadway. The method comprises the steps of performing construction and drilling a hole in a tunneling working face of the soft rock roadway, installing an anchor rope in the well constructed drilled hole according to convention, placing a Z-shaped grouting pipe on an orifice of the grouting drilled hole, laying a reinforcing mesh attached to the surface of the roadway around the orifice of the grouting drilled hole, installing a tray and a lock at an exposed end of the anchor rope, and applying pretightening force on the anchor rope; spraying slurry on the surface of the soft rock roadway, enabling a sprayed layer on the surface of the soft rock roadway to be covered on an outer wall of the grouting drilled hole; and after the sprayed layer is stabilized, grouting the grouting drilled hole through an exposed port of the Z-shaped grouting pipe until the slurry is filled in the drilled hole to achieve total length anchoring of the anchor rope. Finally, effects of reinforcing a surrounding rock structure, improving surrounding rock bearing capability and controlling surrounding rock deformation are achieved.