To provide the basis for parameter selection of pathological voice recognition, an asymmetric modeling method is proposed to simulate diseased vocal fold. According to the layered structure and tissue properties of the vocal fold, a mechanical model is set up to produce the voice source with the straight airflow expelled by lungs. An inversion procedure adopting genetic particle swarm optimization based on quasi-Newton method (GPSO-QN) is developed to adjust the parameters of the vocal fold model and to reproduce the targeted voice source. Experimental results show that the vocal fold mechanical model can produce the voice source that is consistent with the target. In addition, the optimized parameter sets show that the asymmetries of two opposing vocal folds result in the pathology voice.