The quality of smooth blasting is directly related to the quality, safety and cost of tunnel construction. In the blasting excavation construction of Niujiaoshan tunnel, PDCA cycling quality administration method is adopted. According to the overbreak data collected from TM tunnel cross-section measurement system, in-situ inspection, discussion and analysis were carried out with the main influencing factors of smooth blasting being found out. Through formulating special improving measures and supervising implementation, the effect of smooth blasting is well improved. The average qualified rate and residual rate of blast hole reach to 95% and 85% respectively. The construction quality of tunnel is improved, the construction cost is decreased and construction progress is accelerated. In conclusion, favorable quality and economic effects are achieved.