Abstract: "Cutting is the key to speed" in rock roadway excavation. In view of the current problems of ordinary straight and oblique cut blasting, such as difficult to throw broken rock, small single-cycle feed length and high bulk rate, the deep-hole-in-hole piecewise blasting technology is proposed. Using mathematical modeling method, the formulas of dynamic force and resistance in the process of rock crushing and throwing in the deep hole-hole segmented blasting cavity are derived. The relationship between the volume of the cutting cavity, the total blasting cavity and the rock crushing coefficient is established, and the calculation formula and value range of the main parameters of the cutting cavity are determined. LS-DYNA numerical simulation was used to analyze the propagation law of stress wave in deep hole-hole explosion and the stress characteristics of rock at the bottom of the hole, and the variation characteristics of the stress wave intensity under different proportions of the borehole were compared. The deep hole-hole segmented blasting is applied to the rock roadway excavation site , and the blasting effect indexes such as single-cycle footage, hole utilization rate, eye mark rate and bulk rate are compared between the deep-hole-in-hole subsection blasting scheme and the common wedge blasting scheme. The results show that the dynamic force in the process of rock crushing and throwing is greater than or equal to the resistance, and the rock can be thrown out of the cavity. The resistance of rock throwing by deep hole-hole segmented blasting is smaller than that by ordinary wedge cutting blasting, it is easier to blast into the cavity. The measures are put forward to make the broken rock throw out the cavity completely, and the theoretical support is provided for the determination of the parameters such as the distance of the bottom of the cut hole. The deep-hole-hole segmented blasting is easier to form the blasting cavity than the ordinary wedge cutting blasting, and the optimal proportion of the hole segmented is preliminarily determined to be 0.6. Deep hole-in-hole subsection blasting increases single cycle footage, improves work efficiency, and has good economic and social benefits.