Abstract: Recently, graphene foils are considered a promising material for space detection applications due to their minimal thickness. For comparing the specific performance of graphene and carbon foils in film-type Time-of-Flight (TOF) systems, a detailed computer simulation in a definite TOF system is conducted by integrating SRIM, the particle transmission simulation software, with SIMION, the particle optical simulation software. TOF simulation results focused on various aspects of TOF system performance are obtained, such as TOF spectra, scattering distribution, scattering angle, and detection efficiency. These parameters of the TOF system provide reference to the ability of mass spectrometric differentiation and simulation results show that graphene foils applied to the satellite-borne TOF system have higher spectral resolution, shorter scattering radius, lower scattering angle, and higher detection efficiency compared to carbon foils. Graphene’s better performance is derived from its lower thickness, which causes less scattering during ion transmission into graphene. These findings indicate that using graphene foils instead of carbon foils can improve the performance of film-type TOF systems. Further validation of this conclusion requires corresponding experimental test data and results. The conclusion can be referred to the practical testing of graphene foils and other related research, which can make progress for the final practical facilitation of graphene on in-flight TOF systems.