Abstract: China, one of the world’s largest agricultural countries, inevitably generates a massive amount of agricultural solid waste (ASW) every year.  As it is estimated, China annually produced 3.8 billion, 900 million and 200 million tons of livestock and poultry manure, crop straw, and agricultural product processing waste, respectively (Cong et al. 2020).  As an important renewable resource, ASW has great potential and value for resource utilization.  Efficient utilization of ASW is not only beneficial to environmental protection, but also provides great economic benefits.  Since the beginning of the 21st century, research has been fruitful on how to utilize livestock and poultry manure by microbial conversion (Chen et al. 2019; Feng et al. 2020).  However, we have not yet fully understood the changes in microbial diversity and its interaction with different heavy metals during the microbial conversion process of crop straw and agricultural product processing waste.  In addition, insect-based bioconversion (i.e., by earthworms, black soldier flies, etc.) is an emerging and high-value method for ASW treatment.  However, more research is needed to identify the factors influencing the insect-based bioconversion process, investigate the role of microorganisms, and explore the conversion mechanisms in which ASW is converted into multiple valuable commodities by insects, such as proteins, biofuels, fertilizers, etc.  Therefore, in this special focus of ‘Resource utilization of agricultural solid waste’, five papers, respectively contributed by Chang et al. (2021), Cui et al. (2021), Liu et al. (2021), Wang et al. (2021) and Zhang et al. (2021), showcase the latest research progress on ASW utilization.  Chang et al. (2021) report the dynamics of microbial diversity during crop straw composting.  Cui et al. (2021) demonstrate that the addition of phosphate rock in swine manure and maize straw composting could reduce the bioavailability of heavy metals by influencing the bacterial communities.  Liu et al. (2021) evaluate the feasibility to employ stevia residue in eco-friendly fermentation of Trichoderma guizhouense.  Wang et al. (2021) investigate the changes in speciation, mobility and bioavailability of different heavy metals during the conversion process of pig manure by black soldier flies.  Zhang et al. (2021) summarize the functional characteristics of microorganisms, influencing factors (such as larval density, manure temperature, type of manure and so on), and possible mechanisms during the conversion processes of livestock and poultry manure by black soldier fly larvae.  It is hoped that the studies presented in this special focus could enhance our basic and applied knowledge in the field of resource utilization of ASW, and stimulate further innovative research in this area.