The present invention provides an excitation control circuit, a control method using the same and an electrically excited wind power system having the same. The excitation control circuit comprises at least one converter and at least one AC/DC conversion module. The converter is located between an AC electric grid and a wind power generator, so as to convert AC power generated by the wind power generator into AC power corresponding to the AC electric grid. The input side of the AC/DC conversion module is electrically connected between the converter and the wind power generator, and the output side is coupled to an excitation device. The AC/DC conversion module is used to convert the AC power from the wind power generator into a DC voltage, and provides an excitation current for the wind power generator using the DC voltage.