Abstract: This article proposes a direction finding method based on digital multibeam amplitude comparison. Based on the measured phase difference of the longest baseline, all the fuzzy solutions of the incident angle are calculated, and the digital beams are formed on the azimuth of the fuzzy solutions of the incident angle by using the phase difference of each baseline, furthermore, the direction finding results are obtained by resolving the ambiguity of beam amplitude comparison, and the concept of fuzzy reliability margin is proposed innovatively. The feasibility of the direction finding method, the relationship between the reliability margin and the performance of the method, and the comparison with several traditional methods are studied by simulation. The simulation results show that the method is feasible, the relationship between the reliability margin and the probability is positive, the method shows good direction finding effect, and the probability is better than the traditional direction finding method.