The invention relates to the technical field of rock roadway blasting, in particular to a sub-stage subsection efficient deep hole cutting blasting method for a rock roadway. According to the sub-stage subsection efficient deep hole cutting blasting method, in-hole subsection and inter-hole sub-stage are adopted, a millisecond delaying blasting method is adopted by all stages, the size of a cutting cavity is increased, the free face of single blasting is enlarged, and the blasting efficiency is improved; and energy formed by blasting can be released in the direction of facing the free face andin the inward direction, and the vibration effect caused by the blasting is greatly weakened. Blasting is conducted according to the blasting sequence of first section explosive in a first stage cutting hole, explosive in a center cutting hole and second section explosive in the first stage cutting hole, explosive in a second stage cutting hole, explosive in auxiliary blast holes and explosive inperiphery blast holes by adopting the mode of millisecond delaying blasting, and whole section one-time blasting is completed; and the size of the cutting cavity can be increased, the free face is enlarged, and the blasting efficiency is improved.