When the hull structure and its mechanical and electrical equipment are working normally, there will be a steady load acting on the launcher, which will cause the dynamic response of the underwater launcher, thus affecting the reliability and accuracy of the missile. The analysis of the transmission path contribution of underwater launcher can help researchers control the vibration of the path with more efficient method, which plays an important guiding role in vibration reduction.Based on the power flow finite element method, the contribution of vibration transfer path of underwater launcher is analyzed. Firstly, the dynamic vibration transfer path model of underwater launcher is established, and the vibration response is analyzed by solving the dynamic model.Then, the contribution of each vibration path under different forms of loads is analyzed based on power flow. The results show that the longitudinal shock absorber is the main transmission path under longitudinal excitation.Under horizontal excitation, horizontal shock absorber is the main transmission path.Because there are more vibration modes in the horizontal direction and the stiffness of the horizontal shock absorber is larger, the power flow transmissibility is higher under the transverse excitation.The research results can be used as a reference for the dynamic design and optimization of underwater launcher.