Abstract: A passive tracking system consisting of multi-radar reconnaissance stations usually uses the time difference of arrival (TDOA) tracking measurement method, which can achieve high tracking precision. However, when the communication among these stations is interfered, the measurement error of the TDOA method will increase and thus the tracking precision of the system will deteriorate. In this paper, a new fault-tolerant tracking algorithm is proposed, in which both the TDOA method and the directions of arrival (DOA) method are used. In each period, the state variables of targets will be detected with χ2 to determine whether the switchover from the TDOA method to the DOA method should be made. The analysis shows that the proposed algorithm is characterized by high anti-interference while its tracking precision does not deteriorate. Some simulation experiments are used to verify the validity of the new algorithm.