In order to simulate conoscopic interference in uniaxial crystal under different optical axis directions, beam divergence angles, crystal thicknesses or incident wavelengths, a method of writing and running an Advanced System Analysis Program (ASAP) command script was adopted. Functions of main commands were as follows: define geometries and optical properties of a polarizer, a crystal, an analyzer and a plane for observing interferograms. Create a set of divergence Gaussian beams and specify their coherence and propagation. Trace rays, calculate and display the exact complex field energy distribution characteristic on the observing plane. Simulation results show that, when the optical axis is perpendicular to the crystal surface, the interferogram consists of concentric interference fringes centered on the optical axis and is separated by a cross. When the optical axis is parallel to the crystal surface, the interferogram consists of two sets of hyperbola interference fringes with their symmetrical axis separately perpendicular and parallel to the optical axis. Their fringe densities both increase from inside to outside. When the optical axis is neither perpendicular nor parallel to the crystal surface, characteristics of the interference fringe vary with the specific directions of the optical axis. Once increase the beam divergence angle and the crystal thickness, or reduce the incident wavelength, fringes of the interferogram will move toward inside with their numbers increasing, and vice versa. The interferogram appearing when the polarizer is perpendicular to the analyzer is complementary to that appearing when the polarizer is parallel to the analyzer.