Based on the vectorial Debye diffraction theory and taking linearly polarized anomalous hollow beam as an example, the phase singularities in the focal region are studied. It is found that electric and magnetic phase singularities depend on the truncation parameter and numerical aperture. By varying the truncation parameter, the motion, creation and annihilation of phase singularities of electric and magnetic field take place in the focal region. By companying phase singularities, a pair of saddle points may appear and behave similarly. A pair of saddle points and the corresponding pair of phase singularities approach, and then annihilate each other, which leads to the subwavelength structure. However, the singularities annihilate behind saddle points. There exists the different critical point of truncation parameter, where the creation or annihilation occurs at the same numerical aperture. The results are illustrated and compared by numerical examples.