Abstract: The traditional double long baselines interferometer (DLBI) requires the baselines to be strictly co-prime for locating. Besides, it is sensitive to the phase error and the performance becomes worse with higher fuzzy number. In this paper, an improved direction-finding algorithm with double baselines rotating interferometer (DBRI) was proposed to solve the drawback mentioned above. Two baselines with arbitrary length, rotating in the opposite direction with arbitrary palstance, were utilized to get the phase difference for locating. Finally, the computer simulations were carried out to verify the effectiveness and validity of the proposed algorithm. Results show that, the algorithm can obtain better location precision with high fuzzy number and robust to the phase error.