In order to describe explosion process of pre-formed fragment warhead accurately, a warhead explosion simulation system was established. In the system, the dynamic explosion power field was formed with integrated functional modules. With material parameter modification and algorithm improvements, the fragments' field was visualized based on UG modeling and LS-DYNA simulation results, and the data file of fragments scattering characteristics were built by developing interface-processing programs with C++ Taking an example of a certain type of pre-formed fragment warhead, the results were consistent with the theory and the system was proved effective and reliable, which provides a reference for the pre-formed fragment warhead design and performance evaluation.