The invention provides a blocking filtering method for inhibiting subsynchronous resonance of a series compensated transmission system of a doubly-fed wind power plant. The series compensated transmission system comprises a DFIG (Doubly-Fed Induction Generator) wind power plant and the series compensated transmission system connected with the DFIG wind power plant, wherein the wind power plant comprises induction motor, a power electronic converter and a power electronic converter control system; the method comprises the steps: selecting a blocking filter, wherein the blocking filter is used for filtering an SSR (subsynchronous resonance) modal signal in a control signal of the power electronic converter control system; analyzing a subsynchronous characteristic of the series compensated transmission system of the doubly-fed wind power plant and determining the characteristic frequency and bandwidth of the blocking filter; analyzing the structure of the power electronic converter control system so as to determine a plurality of embedded points therefrom; and embedding the blocking filter after parameters setting into at least one embedding point so as to filter the SSR modal signal in the control signal of the power electronic converter control system. The method provided by the invention can be used for effectively inhibiting subsynchronous resonance problem of the series compensated transmission system of the doubly-fed wind power plant.