In order to solve the problems of low blast hole utilization, high explosive consumption, and poor roadway formation in a small section trapezoidal rock roadway in a certain mine, the collimation technology was used as the basis, combining the lithology characteristics of the roadway and the existing equipment without changing conditions, blasting parameters such as hole depth, number of holes, charge amount and initiation sequence were optimized, and a one-time initiation technology for full-section of middle-deep holes was made to achieve safe and efficient blasting. This method can not only achieve accurate drilling in a narrow space, but also solve the problem of strong clamping force of the four apical corner rocks, and improve the blasting effect. The blasthole utilization rate increased from 73.9% to 86.9%, and the mining speed was greatly improved.