Metro tunnels often have to cross underneath largescale buildings in urban areas. Vibrationreducing blasting technology on basis of insidehole millisecond detonator and outsidehole millisecond detonator is presented, so as to reduce the influence of the blasting vibration on the building structures. The connection mode of the detonators is series connection, with 3 to 5 holes as a group, and the blasting of each blasting hole is alternative, so as to achieve delayed blasting. In the end, the velocity of the blasting vibration is reduced and the construction safety and quality are guaranteed.