A He-Ne beam is extended by a telescope system and a rotating ground glass is located near the focus of the telescope system. Different coherence degree of partially coherent beam can be obtained by changing the position of the rotating ground-glass plate. A partially coherent vortex beam can be obtained as the partially coherent beam passes through a spiral phase plate and the topological charge varies with the changing of different spiral phase plates. The research shows that the intensity distribution of vortex beam will change with the varying of the coherent characteristics. Moreover, with the decrease of the coherence degree of the incident beam, the intensity of the vortex beam center will not be zero, but increase. The image contrast of the light spot will decrease at the same time. The size of the hollow core of vortex beam has close relationship with the topological charge. The numerical simulations according to the experiment condition agree with the experiment results.