Marine diesel engines use centrifugal compressors as the impellers to supercharge and it is driven directly by exhaust gas turbines. The working process of the impeller is a combination of changing parameters and thermodynamic processes inside the impeller. The technical and environmental conditions of the impeller will greatly affect the working characteristics of the engine. Nowadays, the technology of simulation and calculation of fluid and gas flow dynamics (CFD) is developing and is widely applied in many fields of ships and industry. We propose to research and apply CFD techniques to analyze and simulate the working process of turbocharger impellers for marine diesel engines. The marine diesel impeller CFD simulation program is used to analyze the thermodynamic processes of the impeller and graphically simulate the working states of the impeller at different operating speeds. In this paper, we are using the experimental results to analyze the processes of the Mitsubishi impeller model MET42SC type DA3G installation on M/V VTB BRAVE to verify the simulation results.