Traditional white light sources are typically modeled by a pure Gaussian function，which adjust the interference signal by changing the center wavelength and bandwidth. In this paper，the Gaussian model and the Lorentzian model are used to discuss the white light interference signals，respectively. The larger the ratio of the central wavelength to the coherence length is，the higher the visibility of the zero-order fringes. The reliable range of the Gaussian model is also obtained. In view of the difference between modern white light source and traditional light source，the white LED is used as an example to simulate the influence of modern white light source on white light interference signal. When the Lorentz model is used，the interference signal has a depression. Furthermore，by adjusting the distance between the peaks of the LED fitting light properly，the influence of the depression on the zero order fringes is reduced in order to acquire a better white light source spectrum with interference properties in practical application.