Abstract: In view of the conservative problem of single-cycle footage in the original blasting design of a tunnel，combined with the first-stage construction verification and on-site investigation results，it is found that the actual stability of the surrounding rock of the tunnel is better than the conclusion of the geo⁃ logical exploration report，and it has the safety implementation conditions for increasing the footage of sin⁃ gle-cycle blasting excavation. Based on this，the tunnel excavation blasting scheme is optimized and the targeted safety protection measures are taken. The results show that the optimization scheme can effectively reduce the damage of tunnel structure and surrounding facilities caused by blasting vibration，flying rock and shock wave. The effective footage rate of blast holes in the lithologic integrity area of the excavation section of the tunnel is 86% ~ 96%，and the effective footage rate of full-section blast holes is 81% ~ 92%，and the roof forming quality is excellent. At the same time，it significantly reduces the cost of tunnel excavation and support construction，and greatly shortens the construction period of the project. The opti⁃ mization scheme and implementation experience can provide important technical reference for blasting con⁃ struction of tunnel engineering with similar surrounding rock conditions.

Key words: tunnel excavation, smooth surface blasting, digital electronic detonator, blasting vibra? tion, stability of surrounding rock