Based on the methods of vector angular spectrum and stationary phase, the analytical expressions of the TE and TM terms and the energy flux distributions of sinGaussian vortex beams in the far field were derived and used to analyze the phase singularities and energy flux distributions. It is shown that the farfield properties of sinGaussian vortex beams are dependent on the waist width of Gaussian beam, offaxis distance, position of coordinate and parameter related to the sine functions. Under certain conditions phase singularities and black nuclei of the energy flux distributions will appear in the far field. By changing the controlling parameters of the beams, phase singularities and black nuclei excluding those at the origin will vary. The symmetry of the phase singularities and the energy flux distributions is dependent on the vortex offaxis distance. The distributions of phase singularities and energy flux are symmetrical about the origin in case the offaxis distance is zero. With varying the offaxis distance the asymmetry may take place and the results were analyzed.