By installing hydrodynamic energy-saving devices with front pre-rotation guide wheels (CMES-PSV®) and hub vortex elimination fins (CMES-HVAF®) as the core in the stern area, it is used to improve propeller inflow and recycle wake energy, thereby improving propeller propulsion efficiency and achieving the purpose of reducing main engine power. According to the ship type customization, the front guide wheel saves energy by 3%~8%, the vortex elimination fin saves energy by 2%5%, and the front guide wheel + vortex elimination fin combination saves energy by 310%. Compared with without energy-saving devices, the main engine power can be reduced by 3%10% at the same speed, that is, the fuel consumption of the ship's main engine can be reduced by 3%10%, and CO2 emissions can be correspondingly reduced by 310%; NOx, SOX, etc. Air pollutant emissions can be reduced by about 310%.