The building to be demolished was a framework-tube structure with high structural strength and good stability. It was located in a densely populated area with a complex surrounding environment. To determine a reasonable blasting demolition plan, the “three-dimensional gradual detonation” method was proposed, which was a way of detonation that achieves spatial delay by differentiating the delay time of adjacent blasting column holes in the horizontal and vertical planes of the blasting notch. Then, ANSYS/LSDYNA finite element software was used to simulate and analyze three different blasting schemes: V-shaped detonation, symmetrical detonation, and “three-dimensional gradual detonation” with a delay time of 0.50 s. By comparing the shape and range of blasting muck pile, and energy changes when the structure touches the ground, the blasting scheme “three-dimensional gradual detonation” with a delay time of 0.50 s was finally determined. The results showed that compared with symmetrical detonation, the “three-dimensional gradual detonation” reduced the kinetic energy when the structure touched the ground by 50% and increased the internal energy by 47%. Compared with V-shaped detonation, the kinetic energy when the structure touched the ground was reduced by 36%, and the internal energy was increased by 31%. The use of “three-dimensional gradual detonation” reduces the collapse vibration of the structure and completely disintegrates it, reducing the range of the blasting muck pile. When the delay time is 0.50 s, the width and length of the blasting muck pile and the collapse vibration of the structure are smaller than when the delay time is 0.25 s. The numerical simulation time for the upper part of the structure touching the ground was 3.8 s, while the actual time was 4.0 s. The final formation of the blasting muck pile was at 6.0 s, and the numerical simulation of the building collapse process and the range of the blasting muck pile was in basic agreement with the actual blasting effect.