The invention discloses a doubly-fed wind generating set grid-connection harmonic analysis and treatment method. Based on a doubly-fed wind generating set mathematical model, an electromagnetic transient model of the doubly-fed wind generating set is established; electromagnetic transient simulation calculation is performed on the wind power plant by utilizing an ADPSS simulation system, and the harmonic current and the harmonic voltage injected into the power grid by the wind power plant are obtained; the obtained harmonic current and harmonic voltage input to the power grid by the wind powerplant are compared with limit values respectively, and whether the harmonic current and harmonic voltage input to the power grid by the wind power plant exceeds the standard or not is judged; if theharmonic current input to the power grid by the wind power plant exceeds the standard, an active filter is designed, a wind power plant electromagnetic transient model containing the active filter isestablished, and the harmonic current in the power grid is compensated. The method is based on the wind power plant simulation calculation and harmonic analysis of the ADPSS, and the electromagnetic transient model of the filter is designed specific to the harmonic over-standard condition, thereby playing important guiding significance for evaluating the influence of harmonic waves generated by large-scale wind power plant access to the power grid in the eastern region of inner Mongolia.