Relying on a large-span and small-clearance tunnel project of a primary highway,the effect of tunnel surface blasting is optimized. The main design parameters of tunnel face blasting are proposed,and the reasonable range of values of peripheral eye spacing, resistance line, density coefficient and charge volume are given, and the reasonable charging structure and detonation sequence are given; the construction process and technical points of tunnel face blasting are proposed,and the final blasting parameters are optimized,and the effect of face blasting is significantly improved,the maximum over-excavation and the average over-excavation are reduced by half, and the retention rate of the half-hole reaches more than 85%,and the utilization rate of the tunnel shell hole reaches more than 93%, which is a basis for the guidance of similar projects in the future. More than 85%,the utilization rate of tunnel holes reaches more than 93%, which provides the basis and guidance for similar projects in the future.