Due to the factors such as weak fault-induced signals, change of neutral grounding mode, and complicated fault conditions, fault line selection in non-effectively grounded system has been a technical challenge in actual field. Based on data fusion technology, the information of fault-generated zero-sequence voltages and currents is fully analyzed by means of colony amplitude comparison-based, the fifth harmonics-based and wavelet analysis-based methods. Fuzzy theory is employed to create membership functions of the criteria and weights of each method, which improves the adaptive ability and success rate. A single-terminal radial distribution grid model is constructed in PSCAD/EMTDC to test the performance of the presented method and the calculation results demonstrate the high reliability and applicability of the method.