This study focused on optimizing strategies for hydrogen-methane co-production from enzymatically hydrolyzed corn stover by exploring the effects of timed hydrogen effluent (HE) addition on methane yield and mechanisms underlying the process. Enzymatic hydrolysis initially produced a significant hydrogen yield, and optimal conditions were determined through a design experiment. The addition of HE on day 11 led to a substantial increase in cumulative methane production. The study revealed that HE addition enhanced methane production by stimulating specific bacterial growth and balancing metabolic activities. Furthermore, the life cycle analysis demonstrated a considerable reduction in energy consumption and carbon emissions, highlighting the sustainability of the co-production system. By integrating enzymatic hydrolysis with hydrogen-methane co-production processes, the research aimed to improve resource utilization efficiency and promote the transition towards low-carbon energy systems. Overall, the study underscored the potential of utilizing corn stover for bioenergy production and the importance of optimizing co-production processes for sustainability.