It is a hot issue to detect and extract the infeasible paths in the test oriented the function calling relationship. In this paper, an algorithm is proposed to extract the infeasible function paths. By traversing the source codes and analyzing the conditional branch correlations, the proposed algorithm builds a mathematical model oriented the control flow, data flow and the correlations between the modules. The experimental results show that the algorithm can extract the infeasible function paths efficiently and accurately. The algorithm can save the testing cost effectively and improve the testing efficiency.