A straight hybrid plasmonic waveguide (HPW) with concentric nanoring and nanodisk is numerically investigated based on a three-dimensional finite-difference time-domain method. It shows that the straight HPW and the nanoring with variational geometry parameters possess different coupling efficiencies at the telecommunication wavelengths. With different coupling processes, effective coupling can be achieved which provides a way to achieve optimal transmittance. Under an appropriate geometry parameter regime, the HPW could simultaneously offer a large split ratio and provide subwavelength field confinement and long propagation distance. The wavelength responses show that the HPW has good wavelength toleration around 1550 nm, indicating that it may be employed as an optical device with the desired performance for optical communications.