To research the operating characteristics of dual stator-winding induction generator(DWIG) in wind power generation system，the operating mechanism and features of DWIG with the speed change as well as the load change are analyzed based on the equivalent circuit and phasor diagram. And then，the calculation methods of control winding current with different loads are derived. Furthermore，aiming at the rated and variable speed operation modes，the operating characteristics of a 18.5 kW DWIG with inductive load are analyzed in detail. The results show that the control winding can regulate the excitation reactive power to build up the no-load voltage. With the increase of the load current，the control winding current and the slip ration increase，and the efficiency increases first and then decreases. The control winding can regulate the reactive power in variable speed condition for constant voltage output. The correctness of the research is verified by the consistency of the theoretical analysis and the simulation results.