The invention discloses a fault positioning method used for a power distribution network and comprising multiple T-connection inversion distributive power sources. The method includes steps of electrifying a relay protection device; initiating circuit parameters; acquiring power of the distributive power sources; acquiring voltage phasor and current phasor on two sides of a feed line; calculating output current of the distributive power sources; calculating the magnitudes of comparison voltage on two sides of the feed line; if the comparison voltage is greater than a setting value, determining faults within a feed line zone and starting a fault positioning algorithm; if the faults occur in a specific section, calculating a measurement distance percentage, and determining the faults within the section if the measurement distance percentage is smaller than 100%. By adopting the method, problems in relay protection and fault positioning when the multiple distributive power sources are in T-connection with the circuit can be solved effectively. Besides, the method is insusceptible to influence by connection number and connection position of the distributive power sources, fault types and transition resistors, and is high in adaptability and engineering practicality.