Extensive studies of typical accident scenarios are crucial to the development and safety assessments of a novel gas-cooled micro reactor (GMR). At present, few existing computer codes are directly applicable to the GMR. This work is aimed at developing a numerical tool dedicated to the GMR design and subsequently investigating the transient response of the GMR during typical accident scenarios. A generic CFD code, COMSOL Multiphysics, was employed to create this model. Specifically, a point kinetic module was developed and coupled with the TH module. Then the computational model was used to simulate the MHTGR benchmark problem. Comparisons of the predicted results and reference values show a good agreement, thus validating the model. The steady-state case under the normal operation condition was first calculated, which served as the initial condition for the subsequent transient analyses. Thereafter, three represented postulated accident scenarios were analyzed: (1) pressurized loss of forced cooling (PLOFC), (2) PLOFC without scram (PLOFC + ATWS), and (3) reactivity insertion without scram (RIA + ATWS). Simulation results show that the peak fuel temperature throughout the progression of all accidents analyzed in this paper is far below its upper limit (1620 ℃), thus exhibiting a good inherent safety feature. The RIA + ATWS accident is the most challenging scenario that should receive a great concern. The ATWS-type accidents always experience an oscillation of both the reactor power and the peak temperature due to the negative temperature feedback. Increasing the heat removal capacity of the PCCS can relieve the PLOFC consequence, but it may lead to a higher core temperature for ATWS-type accidents. To conclude, the computational model developed in this work can support the safety assessments for the GMR.