By comparing the continuity and resolution of virtual image at “point convergence criterion” and “phase difference criterion”, it is proposed that the former is more suitable for virtual image model of wide-angle velocity interferometer system for any reflector (VISAR). Based on “point convergence criterion”, the effects of ellipsoidal mirror parameters, image recording method and shock wave tilt on the virtual image of the wide-angle VISAR target are analyzed. It is discovered that the ratio of outer and inner diameter of the virtual image is about 8 and the ellipsoidal mirror processing error has little influence on image surface when $ {10^{ - 5}}\left( {k - 400} \right) \lt m \lt {10^{ - 5}}k $ (k and m are the shape parameters of wide-angle VISAR target), it is difficult to obtain dynamic interference fringes in plane detection and wide-angle VISAR diagnosis allows the average inclination angle of shock wave not to exceed 2°. Issues such as virtual image interference of wide-angle VISAR, processing of special-shaped fiber optic panels, selection of ellipsoidal mirror parameters and image reconstruction are discussed, and some suggestions for diagnostic experiments are given. The research on properties of virtual image lays a foundation for the improvement of wide-angle VISAR diagnostic capability, and is of great significance for the symmetry diagnosis in inertial confinement fusion.