Firstly， this paper focuses on the unique identifiability of electrical parameters of direct-drive permanent magnet synchronous generator（D-PMSG） wind turbine with the condition data of no-load and multi-stable operation points. Secondly， a preferred initial value and micro-variation search algorithm is adopted and the detail procedure is given to deal with measurement errors. Finally， the electrical parameters of a D-PMSG are identified on the basis of practical data， validating the correctness of the theoretical analysis and the algorithm.