We have proposed a novel surface plasmonic nanolaser based on a nanowire/air gap/metal thin film hybrid structure to carry out theoretical research and simulation analysis. Opening an air groove in the MgF2 insulating layer, then making a nanowire embedded on the top of the air slot but maintaining a gap between the nanowire and the metal layer, thereby we produce a coupled hybrid plasmonic waveguide and a significant field enhancement effect. This structure enables the realization of an air gap. By simulating the modal properties and the lasing threshold of the hybrid plasmonic mode under different geometric parameters, the capacity of subwavelength scale with low propagation loss and high field confinement is demonstrated. Finally we achieve the nanolaser's optimal structure size. Compared with the general diffraction limit laser, this structure can reduce the physical size of the device and the physical mode. The proposed nanolaser could be easily integrated with various nanophotonic devices, and it may become an appealing candidate for future active plasmonic systems.