Abstract: The large-scale application of doubly-fed wind turbines has significantly changed the fault transient characteristics of power systems. The short-circuit current contributed by doubly-fed induction generator（DFIG） should be fully understood to ensure the implementation of the planning and protection of power system. However, the impact of the converter excitation control has not been fully assessed,thus resulting in greater difficulty in the analysis and calculation of short-circuit current. This study presents a detailed analysis of short-circuit current of a DFIG, with focus on the complex coupling between the excitation control and electromagnetic process. The transient disturbances and their transitive relation in a DFIG under symmetrical short circuit are analyzed by constructing the dynamic model of rotor circuit. The expressions of rotor and stator short-circuit currents are deduced for the simplified calculation and analytical analysis. The characteristics of the short-circuit current of DFIG under the excitation control are analyzed and the impacts of control mode on the transient behavior are presented. The time-domain simulation is adopted to verify the validity of the theoretical analyses.