Electron vortices are a key element in the sub-ion magnetic hole. Here, we investigate the electron velocity inside two sub-ion magnetic holes in the solar wind based on the Magnetospheric Multiscale (MMS) mission. We find that the observational electron velocities inside the magnetic holes are contributed by the combination of the electron diamagnetic (V e,dia), E × B (V e,E), magnetic gradient (V e,▽B) and curvature (V e,R) drifts. V e,dia , V e,▽B , and V e,R are comparable, while V e,E is very small inside the hole. The weak V e,E could result from the electric field approximately perpendicular to the magnetic field inside the structure. The value of V e,▽B + V e,R is near 0; thus, V e,dia is approximately equal to the observational electron velocity. The current density contributed by the electron diamagnetic, magnetic gradient and curvature drift motions is self-consistent with the magnetic depression inside the hole, suggesting that these three electron drift motions play a crucial role in stabilizing the magnetic hole in the mirror-stable astrophysical plasma environment.