The invention relates to a system for detecting a software bug triggered during practical running of a computer program in the technical field of computers. The system comprises a binary code dynamic inserting module, a program basic block recognizing module, a function call graph constructing module, a control flow graph constructing module, a function recognizing module and a static analysis module. By combining two technologies of dynamic program analysis and static analysis path complementation, the invention not only can detect the bugs which can be triggered during the practical runningof the program but also can reach higher program path coverage rate, carry out bug detects on the path which is not covered in the dynamic analysis process, improve the success rate of bug detection and reduce the false rate of the bugs. Meanwhile, the static analysis path complementation technology only analyzes a path which is not executed in dynamic analysis instead of all program paths, thereby greatly reducing the cost on time and system resources.