To address the high algorithm complexity and low timeliness in existing circular array interferometer direction finding methods for building systems， this paper proposed an interferometer direction finding method suitable for system implementation， which was then used in actual systems. First， this method first improved the conventional calculation method for the range of fuzzy numbers based on the amplitude comparison direction finding （ACDF） results， thereby reducing computational complexity and improving processing speed. By considering that higher frequencies enhance ACDF accuracy under the same conditions， the method dynamically segmented the amplitude comparison range in real time by integrating the frequency information and the ACDF results. Then， by taking advantage of the fact that the fuzzy multi-valued differences of each baseline are relatively large， while the true angle has a unique property， the ambiguity resolution for the circular array interferometer direction finding was achieved. Finally， based on the proposed method principle， a miniaturized eight-element uniform circular array interferometer broadband receiver was implemented and designed using an FPGA. Both simulations and field experiments verified that the system achieves high-precision instantaneous direction finding for a radiation source target， with an accuracy of up to 1.5°， demonstrating strong practical value for engineering applications.