The invention provides a wind power plant flickering transfer calculating method based on system impedance and a wind power plant flickering transfer calculating device based on system impedance. The method comprises the steps of acquiring the long-time flickering value P(1t, WF) of a wind power plant grid-connected point, calculating the short circuit capacity S'(sc, PCC) of a point of common coupling flowing to the wind power plant grid-connected point, and the short circuit capacity S'(sc, PCC) of power grid flowing to the point of common coupling when the wind power plant grid-connected point is in short circuit, calculating the long-time flickering value of the wind power plant grid-connected point, transferring the long-time flickering value of the grid-connected point to a transfer coefficient Tk of the point of common coupling, and calculating the long-time flickering value P(1t, PCC) caused by the wind power plant at the accessed point of common coupling. The adopted device comprises an acquisition module, a signal receiving module, a processing module, a wireless internet of things assembly, a remote server and a collecting app. Compared with the technology of calculating the transfer coefficient by utilizing the existing power system simulation software, the technical scheme provided by the invention has the advantages that the complexity and uncertainty caused by modeling of the wind power plant can be effectively avoided, and convenient, time-saving and effective effects are achieved.