Surface plasmon polariton (SPP) waveguides have been paid extensive attention for their unique properties, such as breaking the diffraction limit of light and providing subwavelength mode confinement. Surface plasmonic waveguides proposed before scarcely involve the tunability of the mode confinement and propagation loss by adjusting the geometric parameters. Here, a wedge-like surface plasmonic waveguide is proposed and its properties are investigated by finite element method (FEM). The wedge-like surface plasmonic waveguide features ultra-deep subwavelength mode confinement. The mode confinement and attenuation of the wedge-like surface plasmonic waveguide are controllable by adjusting the waveguide parameters, which makes the wedge-like surface plasmonic waveguide more flexible and could meet different requirements for mode area and propagation length at the same wavelength.