Abstract: The operation data of the actual projects showed that the stable operation characteristics of the double-fed induction generator-based wind power grid-connected system were closely related to the wind speed. The existing analysis methods were only suitable for stability analysis under specific wind speeds, and cannot be extended to the oscillation risk assessment under the whole wind speed operating space. In order to accurately characterize the port characteristics of the DFIG with the full wind speed range, the wind speed was introduced into the traditional admittance model, and the influence of the frequency coupling, the DC bus dynamic and the excitation were also considered, and the two-variable (i.e. wind speed and frequency) admittance model of DFIG was established. Then a stability analysis method based on the two-variable admittance was proposed to effectively analyze the system stability under the whole wind speed range. The DFIG-based grid-connected system with series compensation was taken as a typical case for simulation and analysis, and the accuracy of the model and the validity of the analysis method were verified. The research results provide an important reference for the oscillation analysis and effective suppression of the new energy grid-connected system.