The invention provides a dynamic symbolic execution method and a device of the dynamic symbolic execution method based on an overall situation super block dominator graph and belongs to the field of computer software testing and software security. The method is as follows: a control flow diagram of a tested executable program is obtained, and the control flow diagram is transformed to a super block dominator graph according to relevant theories of a dominance relation. Each nodal point in the super block dominator graph is marked with 'weight' which is updated before symbolic execution at each time, and the 'weight' indicates the least number of basic blocks which can be covered when the nodal point is executed. When one dynamic symbolic execution is over, the nodal point with the largest 'weight' value is selected from the super block dominator graph, and corresponding forecasting path constraint conditions are generated, and then a new testing use case is generated by solving of a solver, so that the next execution is driven. Compared with the prior art, the dynamic symbolic execution method and the device of the dynamic symbolic execution method based on the overall situation super block dominator graph are capable of covering code blocks as many as possible with least testing use cases, so that the growth rate of the code coverage rate is effectively accelerated, and the problem of path explosion is relieved. The dynamic symbolic execution method and the device of the dynamic symbolic execution method based on the overall situation super block dominator graph is of great importance for the performance of testing large-scale utility software of the dynamic symbolic execution.