Most of the small wind turbines are designed with no control or passive control due to the cost consideration. However, both of the two types still have to be improved in terms of the electric generation performance. Thus, the objective of the paper is to improve the electric generation performance and develop an active-controlled 2kW small wind turbine. First, the study is to develop the co-simulation analysis of aerodynamics, mechanism dynamics and control system dynamics for the active-controlled 2kW small wind turbine. Three softwares, including FAST, ADAMS, and MATLAB/SIMULINK, are used for aerodynamic, mechanism dynamic and control system dynamic simulation. The dynamic variations of blades, power transmission system, generator and tower can be analyzed under different input of wind. The closed-loop simulation of the directly-driven permanent magnet synchronous generator, the variable-pitch control and the variable-speed control can be performed by MATLAB/ SIMULINK. By integrating the control strategy and theory, we can realize the maximum power output by tracking the speed that the tip-speed ratio corresponding to under the rated wind speed. While the wind speed is above the rated wind speed, the DC servo motor-driving variable-pitch control system starts to perform. To keep constant rated rotor speed and rated power output, the pitch angle can be adjusted by the pitch control system. Finally, the system of the active-controlled 2kW small wind turbine can be achieved.