The invention discloses a method for identifying the operation topology of a distribution network based on multi-source data fusion, which comprises the steps of installing a DSCADA measurement devicein the distribution network, and installing a [mu]PMU measurement device at nodes at two ends of a tie switch and multi-branch nodes with the degree being greater than 2; measuring the voltage phaseof the installation nodes by the [mu]PMU, and constructing a topology change time identification model so as to determine the topology change time; constructing a topology change trend criterion basedon voltage changes of the nodes before and after the topology change so as to determine the branch range in which the operation state changes, and enumerating all possible topology cases after the reconstruction; and integrating DSACAD and [mu]PMU remote measurement data, constructing a distribution network state estimation model, and carrying out state estimation on all possible topologies; andconstructing a topology similarity identification model to identify the actual topology, thereby improving the reliability of distribution network topology identification. The method has good applicability in the cases of single tie switch operation and multiple tie switch operation.