Treatment and resource utilization of biowastes have emerged as environmental and economic challenges. Among the waste management strategies, solid-state anaerobic digestion (SS-AD) stands out for its ability to offer a multitude of positive environmental benefits. SS-AD is particularly suited for the anaerobic digestion of high-solid-containing substrates (Total solids (TS) concentration greater than 25%), such as agricultural waste. Continuous research and technological innovation are essential to further improve the efficiency and feasibility of methane produced from biowastes via SS-AD, promoting the sustainable utilization of biowaste resources. This chapter provides a comprehensive overview of methane production from biowastes via SS-AD, focusing on its technological principles, influencing factors, optimization strategies, applications, and prospects. By summarizing the effects of temperature, C/N ratio, total solid content, inoculation, and other factors on the produced from biowastes via SS-AD, it offers a reliable solution to enhance methane production rate of SS-AD.