SmB6 is believed as an ideal candidate for FE applications because of their unique properties. Up to date, the effect of image potential on the field emission (FE) behaviors of one-dimensional nanostructures is still unclear in experiments, and thus it becomes a challenging issue for the researchers. In this paper, the effect of image potential on FE properties of SmB6 nanowires are detailed studied by combination of experimental results and the generalized Schottky-Nordheim (SN) model. The experimental results show that they have a turn-on field of 3.4 V/μm (at 10 μΑ/cm2). Meanwhile, the image potential factor of SmB6 nanowires is calculated to be equal to 1 based on our model, which is resemble to ideal metal plane.