With the development of mechanics and computer technology, computer simulation has become an important tool in the structure analysis and design. Especially when the structures are under disaster load such as blast, penetration, impact of collapse or typhoon, it is difficult to analyze with test method, while the advantages of computer simulation method such as safe, efficient and cheap, are shown obviously in these problems. Various simulation systems are classified and discussed in this paper generally. And four practical examples are presented to demonstrate the function of simulation system. The first one is the analysis for the safety of blast-resist-doors under blast load. The second one is the study on new earth-penetration-weapons. The third one is the simulation on the collapse ofWorld Trade Center (WTC) in New York. And the forth one is the real-time display system for bridge under typhoon. These examples are used to illuminate the advantage of computer simulation technology on disaster load conditions and emphasis some problems in the simulation.