Abstract: The complex power quality disturbance event contains multiple related basic events and disturbance event sources. Based on the discrimination of disturbance directions at the segment time, this paper proposed a complex power quality disturbance event source localization method based on the measure weighted fuzzy Petri net. On the basis of the disturbance power and energy at the segment time, the disturbance direction was discriminated. And using the path table of power transmission, the suspicious branch was determined. Then, according to the comprehensive disturbance intensity and the reliability of the disturbance direction result, the state measure extraction method was given. Finally, the measure weighted fuzzy Petri net was used to locate suspicious disturbance event source. The results show that the proposed method can achieve the source location of complex power quality events which contains multiple related basic events and disturbance event sources, and has strong fault tolerance performances.