Abstract: ‍ ‍With the rapid development of 5th generation （5G） wireless communication technology， passive radar technology based on 5G signal has shown great potential for application in target monitoring. In particular， in a distributed system， a passive radar system could combine information from multiple stations distributed over a large range to jointly complete complex target detection tasks， opening up novel ideas and methods for passive radar target positioning technology. However， in the distributed scenario of 5G base stations， most of them are deployed in complex environments， leading to increased measurement errors in the target localization process， thereby limiting the accuracy of target localization. Therefore， developing novel methods and techniques to improve the accuracy of target localization in a distributed 5G base station environment was necessary. This article introduces a solution to the problem by utilizing the unique positioning reference signal （PRS） of 5G and proposing an iterative three-step weighted least squares （I3WLS） algorithm for accurate target localization in distributed passive radar systems. The first step in the proposed algorithm was to establish a target echo model based on 5G signal and construct the range difference of arrival （RDOA） equation using echo delay information. The second step involved the use of the weighted least squares algorithm to update and iteratively optimize the initial estimation value of the target position. Finally， the third step utilized the linear transformation distance constraint equation to retain the first-order term of the target position， resulting in an accurate estimation value of the target. The simulation results demonstrate that the proposed I3WLS algorithm outperformed existing methods in terms of positioning accuracy and robustness. The algorithm’s ability to accurately localize targets in distributed passive radar systems shows promise for practical applications in various fields， including surveillance， navigation， and communication. In conclusion， the combination of 5G signal and the proposed I3WLS algorithm offers a promising approach for achieving precise target localization in distributed passive radar systems. The algorithm’s ability to mitigate positioning errors and optimize the estimation of target positions demonstrates its potential to advance the field of passive radar target positioning.