Abstract: In order to carry out the research on locating the source of global navigation satellite system (GNSS) interference, a model of multipath fading of the interference phase was built and a method of depicting the direction finding distribution was proposed according to the multipath propagation of the interference. Firstly, direction finding model and its theoretical error were listed aiming at GNSS interference. Then, the relationship between phase distribution and Rician factor was simulated and analyzed on the condition of multipath. By the means of inferring the PDF (probability density function,) of phase, a mathematical model of the phase of GNSS interference was built. Finally, a research on the relationship between direction finding distribution and Rician factor along with DOA was carried out, taking advantage of the Monte Carlo simulation. The theoretical derivation and simulation results indicate that the phase of interference follows Gaussian distribution on the condition of multipath when the Rician factor is pretty large. The variance of direction finding decreases with the increase of Rician factor. The variance is the minimum when the moment DOA is perpendicular to the base line. And the confidence interval tends to stable with the same confidence level while Rician factor is more than 20.