A U-shaped optical slot nanoantenna with a footprint size of 300 nm by 300 nm is proposed to achieve invertible plasmonic spin-Hall effect at nanoscale. The interference between the SPPs excited by the different plasmon resonances in the antenna enables the nanostucture to break the spin degeneracy. Besides, the SPP orbitals for the two spins are invertible while changing the incident wavelength, which is attributed to the dispersive phase shift between the different plasmon resonances in the antenna. The SPP intensity extinction ratio can be improved by employing a U-shaped slot antenna array. The strong spin-orbit coupling property together with the ultra-compact size and invertible spin-controlled SPP orbitals enable the structure promising applications in spin-optoelectronics and plasmonics.