Abstract: Based on COMSOL Multiphysics and MATLAB software, a three-dimensional thermal-hydraulic model was developed for the graphite-moderated channel type molten salt reactor (MSR). The temperature distribution in the solid region was calculated with a three-dimensional heat conduction equation. The heat transfer in the molten salt was modelled by the one-dimensional single-phase flow model. The thermal coupling of fuel salt and solid region was set up through the convective heat transfer boundary condition at the surface of fuel channel. The mass flow rate in each fuel channel was calculated based on the assumption of equal pressure drop over all channels. In terms of temperature and mass flow rate distribution calculations, the result from this thermal-hydraulic model is consistent with that from the RELAP5 code. With the aid of this model, the temperature and mass flow rate distributions in the 2 MWt MSR were analyzed. This thermal-hydraulic model can be used to precisely analyze the temperature and mass flow rate distributions of the channel type molten salt reactor, which is quite useful in the thermal-hydraulic design.