A series of countermeasures, such as sequential excavation by means of drilling and blasting, wedge cut and shot hole stemming, are adopted in order to minimize the impact on the existing tunnel structure caused by the blasting made during the construction of Damaoshan tunnel. Due to the countermeasures taken, the blasting vibration velocity is brought under control. Blasting vibration control standard for different surrounding rocks of large crosssection and closelyspaced tunnels is determined, which is stricter than that for similar tunnels.