In order to analyze the sharing mechanism of marine high-speed star gearing system, a static mechanical model is presented in the paper, in which manufacturing errors, assembly errors, bearing errors and tooth thickness error are all considered. In consideration of equivalent mesh error and static balance of floating components, the load sharing coefficient of the system in different kinds of errors was obtained. And the sensitivities of the load sharing coefficient on different types of errors are analyzed. The result shows that the effects of the eccentric error of sun and tooth thickness error of star gear upon load sharing coefficient are larger than those of the other errors. The influences on load sharing coefficient of each error have cumulative effects. The research has provided a useful reference for improving the load sharing capability of marine star gearing system.