The use of alternative biomass sources that are not competitive with food production is intended for sustainable management in biogas production through anaerobic digestion. This study investigates the Napier grass and cattle slurry-based biogas production application that could be applied more cost-effectively more sustainable production biogas. The laboratory-based biogas plant and a biogas plant in practice revealed that the results from the laboratory experiments were realistic and transferable into practice. The effect of feedstock screening on the biogas yield of Napier grass and cattle slurry was evaluated in batch digesters under mesophilic conditions. Moreover, highest methane content was reached 64.4%. The biogas from the co-digestion of Napier grass and cow farm slurry containing the higher calorific value was 25.69 MJ/m3, and the lower calorific value was 23.14 MJ/m3 . The results demonstrated that combining Napier grass with common cow farm slurry can accelerate the reaction, increase efficiency, and increase methane content. Therefore, the co-digestion of Napier grass and cow farm slurry was a promising method for increasing biogas production.