The research of optical angular momentum and spin-orbit coupling under non-paraxial conditions will help people understand the phenomenon of light in sub-wavelength structures. The evanescent wave in the near field may produce strong spin-orbit coupling. In this paper, based on the angle spectrum diffraction theory and Parseval theorem, the near field evolution characteristics of propagating waves, evanescent waves and angular momentum of Laguerre-Gaussian vector vortex beams on high-order Poincaré sphere are analyzed in detail, as well as the spin-orbit coupling caused by evanescent waves. The results show that the evanescent wave action near the source plane of the beam with sub-wavelength waist width is strong, and dominates the total optical field. Moreover, the orbital angular momentum contains the contributions of both the transverse and longitudinal electric fields in the near field, and the transverse spin angular momentum in the evanescent wave is related to the transverse polarization state, furthermore there is a phenomenon of spin direction locking. The research provides a theoretical support for the study and application of vector vortex beams in sub-wavelength structures.