In the traditional Fresnel biprism interference experiment，the distance from the slit to the screen is directly read out through the optical bench，which brings obvious experimental errors．In this work，the distance from the slit to the screen was calculated by measuring the enlarged image spacing and the reduced image spacing，and thereafter the wavelength of the He-Ne laser was obtained．This method reduces the experimental error effectively and improves the accuracy of the measurement results significantly．Two-and three-dimensional simulations of the experimental interference fringes were carried out by using Mathematica software，giving ideal interference fringe images，which makes the experimental results more visualized．Meanwhile，an exploratory experiment of orthogonal biprism interference was carried out，and the three-dimensional and simulated interference images of the light intensity distribution were obtained by Mathematica．The above research results improve the accuracy of the biprism interference experiment，expand the teaching contents，and achieve the ideal teaching effect．