Taking a blasting demolition project of a 70 m building with a 8.0 m×8.6 m span between stand columns as an example,the impact vibration of the collapsed building on the ground was calculated and analyzed theoretically to ensure the safety of the buildings under construction.The blasting demolition control technologies including double incision accelerating the disintegration of the building in the air and block delay were used to carry out the demolition project.A blasting vibration tester was used for real-time monitoring,and the collapse shape was analyzed by a high-definition camera.The safety and effectiveness of the demolition control technology were then verified.The high-definition photos and vibration monitoring data showed that the potential energy conversion of the long-span building was fast,which could cause recoil easily.Although the damping ditch can significantly reduce the collapse vibration,it had no effects on the blasting vibration.While the floor height where measuring points were arranged had certain amplification effect on the blasting vibration velocity,it basically had no effect on the collapse vibration.