This article introduces an enhanced software program for stochastic ground‐motion simulations using finite‐fault sources, named Ground‐Motion Simulation System version 2.0 (GMSS2. 0). GMSS2. 0 embodies an updated theoretical model of corner frequency and source duration, making the seismological model for defining the Fourier amplitude spectrum for each subfault more theoretically consistent. In addition, GMSS2. 0 provides four rupture scaling relationships and five baseline correction techniques for end users to select the most suitable one for a specific application. For validation purposes, comprehensive comparisons between GMSS2. 0 and EXtended SIMulation (EXSIM) for wide ranges of magnitude (M 4–8), distance (∼ 6–300 km) and spectral period (0.01–10 s) have been performed. The results show that GMSS2. 0 can give remarkably close estimates to EXSIM with reasonable levels of accuracy. Finally, further validation is performed by comparing GMSS2. 0 simulations with five Next Generation Attenuation‐West2 ground‐motion models for multiple scenario earthquakes with the updated site amplification for the generic California condition (⁠ V S 30= 500 m/s⁠).