A new type of composite vortex beam is generated by the coaxial superposition of two Laguerre-Gaussian vortex beams w ith different waist parameters and different topological charge numbers.The offects of waist parameter on the beam distribution and spa ce propagating property of composite vortex beam are respectively investigated in this paper.It′s found tha t the change of waist parameter of one Laguerre-Gaussian vortex beam can control the distance from th e beam center to dark petals (low intensity positions) or bright petals (high intensity positions) on the composite vortex beam. Furthermore,diffraction broadening and Gouy rotation properties can be observed during the space propagation of the new-type composite vortex beam.The optical experiment by a reflective-type spatial light modulator (SLM) verifies the aforementioned results.The research results m ay provide some theoretical and experimental foundations for deep knowledge of the formation,be am distribution characteristics and space propagating property of composite vortex beams.