A software has been developed to predict the inherent longitudinal vibration characteristics of the ship shafting. The software is developed using the QT platform, with the core solver written in MATLAB and the solution algorithm using the Holtz method. The results are compared and verified with the simulation results of ANSYS and the longitudinal vibration calculation results of an actual shafting system. On this basis, the developed software is used to discuss the variation of the longitudinal vibration characteristics of the shafting under different shafting properties. The results show that the properties affecting the inherent longitudinal vibration characteristics of the shafting mainly include the crank radius, crank thickness, longitudinal stiffness of thrust bearings and material elastic modulus. The relevant research results can provide references for the vibration and noise reduction of the ship shafting.