Abstract: Passive hydrogen recombiner is widely used in mitigating and eliminating hydrogen threat in nuclear power plant. GOTHIC 8.0 code was secondary developed through DLL (dynamic link library) compiling and calling, and the eliminating capability of the passive hydrogen recombiner in a more accurate manner was simulated in this paper. The accuracy of this method was verified by comparing the results with correlation calculation and MAAP5 code case calculation, and both results matched well. This paper not only provides a new method for analyzing containment hydrogen risk mitigation, but also provides a new function for developing GOTHIC code.