A dielectric-loaded graphene plasma waveguide is proposed and the mode field distributions and propagation characteristics of the waveguides with different sizes are studied. The simulation results show that, when the chemical potential of graphene is 0.7 eV, and the ridge width and the ridge height are both 1000 nm, the mode width of dielectric-loaded graphene plasma waveguide reaches the minimum value of 1.55 μm and the propagation length reaches 43.47 mm. This dielectric-loaded graphene plasma waveguide not only can meet the requirement of waveguide design, but also provides a possibility of long-distance transmission for nano-devices.