In order to study the blasting technology of the insitu collapse of a cooling tower,the incision was analyzed by finite element software.Furthermore,a highdefinition camera was used to collect the deformation data of the cylinder body and lambdoid stand columns.Then detailed analysis was carried out for the deformation time of the cylinder,the collapse speed,the change of the incision closure,and the collapse range after the distortion and deformation of the cylinder.The practice results show that the incisions for the insitu collapse of the cooling tower cannot be designed as four equal parts as convention.It is easy for four equally distributed parts to cause the bottom part not to collapse.The perimeter of the fourth area(the last initiated part) is slightly larger than that of the first area by a quarter.The inhole delay times in the four areas are MS4,MS8,MS8 and HS3,respectively,and the outhole delay time is MS2.Through the finite element simulation,it takes 1 second to generate the collapse trend of the cylinder,3 seconds to close the incisions of the cylinder,and 6.8 s for the cylinder to squeeze,twist in the air and touch the ground.The deformation of each area must be completed within a reasonable time.By image analysis and calculation after the explosion,the above simulated times are the same as the actual times.90% of the insitu collapsed cylinder is within the pool,and the upper ring beam is thrown out of the pool by about 6 meters,which does not affect the surrounding hydrogen production station,circulating water pump room,steel gate and other facilities.After measurement,the peak vibration velocity the natural gas pipe is only 2.095 cm/s,indicating no impact on the buried gas pipe 23 meters away.The research shows that the insitu collapse blasting technology can effectively control the collapse touchdown vibrations and the collapse throw distance of the cylinder.