Abstract:  In addition to the type of algorithm which is selected, the geometric configuration of the array is also an important factor that affects the performance of Direction-Of-Arrival (DOA) estimation in the array direction-finding system. The relationship between the differential geometry parameters of array manifold and direction-finding accuracy of array is firstly studied by using the tools of differential geometry in the paper. Based on this, the relationship between direction-finding accuracy of circular array and its geometric configuration has been deduced and analyzed, and the factors which affect the performance of DOA estimation are discussed. Finally, an approach to improve the performance of direction-finding of the array system in some directions while one signal is impinging by adjusting the elements’ positions on the circle is proposed, and the validity of the method is verified by comparing and analyzing several arrays with different configurations in computer simulations. It supplies useful reference for the choice of array configuration in actual applications.