Water hyacinth was regarded as a well raw material of anaerobic methane fermentation system. In this paper, water hyacinth was taken as the only material to conduct anaerobic methane fermentation experiment. Water hyacinth methane production characteristics were studied. Then, two-stage model was established to simplified analysis the biogas production process. Results revealed that biogas potential of water hyacinth anaerobic fermentation was 500 mL/gVS, two-stage model was basically consistent with the process of the fermentation experiments with the relative error less than 10%.