Abstract: This paper investigates the stability and noise reduction of active noise reduction headset when virtual microphone is used.The stability of the virtual microphone algorithm is analyzed theoretically.By introducing feedback controller and designing the secondary path model,the algorithm can operate steadily when the position of the headset varies,thus large noise reduction can be achieved with better stability.Experiment confirms that the application of virtual microphone can result in larger narrowband noise reduction at the ear canal entrance,and the proposed measures can ensure stability in different headset positions.