At present, as the product of sewage treatment, municipal sludge has high water content, organic matter, heavy metals, salts and microorganisms, which will cause serious harm to human body and environment if it is not treated properly in time. At the same time, under the condition that the output of straw agricultural waste is more than 5 billion tons worldwide, efficient conversion treatment methods still need to be further provided. Sludge and straw are the main organic wastes in cities and agriculture, respectively. How to realize effective recycling has become a hot issue of global environmental sustainable development. The way to prepare biochar from organic waste is one of the ways to recycle sludge and straw. Biochar possesses high specific surface area, significant porosity, and abundant functional groups. It holds promising application prospects for efficiently adsorbing and removing tar, organic matter, and heavy metals from waste gas and sewage. Therefore, this paper discusses the utilization ways of sludge and straw solid waste, especially the application status and research progress in environmental governance. Because the environmental and economic conditions in different regions are quite different, there is a lack of in-depth analysis of the economy of agricultural straw and municipal sludge-based biochar and the study of its impact after recycling. Subsequent research can continue to carry out related work in the economic aspect.