In this paper, a 3D elastic-plastic and coupled thermo-mechanical FEmodel of radial ring rolling is developed to simulate the rolling process with different feed rates of idle roll v based on the dynamic explicit code ABAQUS/Explicit. Theeffect laws of on the uniformity of strain and temperature distribution, fishtail coefficient, roll force, contact area and roll moment are disclosed respectively. One optimum is obtained, under which the deformation is the most uniform, another optimumis obtained, under which the temperature distribution is the most homogeneous. Moreover, an optimum is obtained, under which the quality of end-plane of rolled ring is the best. The result obtained can provide a valuable guideline to quality control and optimumof hot ring rolling ofmagnesium alloys.