Abstract: New energy electric propulsion technology has become a core direction for the development of ship power systems. Addressing key issues such as difficulties in shafting vibration control, gear transmission efficiency losses, and insufficient torsional vibration suppression in the mechanical transmission links of electric propulsion turbine systems, this paper conducts systematic experiments on a 6000-ton pure electric cargo ship, focusing on three dimensions: shafting dynamics, gear reduction transmission efficiency and thermal characteristics, and coupling torsional vibration suppression. After optimizing the shafting support stiffness, the natural frequency offset decreased by 37.6%, the herringbone gear transmission efficiency reached 98.2% under rated operating conditions, and the peak torsional vibration of the flexible diaphragm coupling was reduced by 52.3% compared to the rigid scheme, providing data support for the engineering design of electric propulsion mechanical transmissions.