We propose new types of hybrid plasmonic waveguides for low-threshold nanolaser applications. Modal properties and lasing threshold under different geometric shapes and parameters are investigated and analyzed by the finite element method, aiming to realize both low propagation and high field confinement. Results show that a smaller gap width and a larger round corner radius of the metal film reduce the lasing threshold. These new structures can open up new avenues in the fields of active plasmonic circuits. We propose new types of hybrid plasmonic waveguides for low-threshold nanolaser applications. Modal properties and lasing threshold under different geometric shapes and parameters are investigated and analyzed by the finite element method, aiming to realize both low propagation and high field confinement. a smaller gap width and a larger round corner radius of the metal film reduce the lasing threshold. These new structures can open up new avenues in the fields of active plasmonic circuits.