Biomass, a renewable resource in nature, has been used by humans for a long time. The value-added utilization of biomass has arisen in recent years due to the energy crisis. Limited by the compact structure of biomass itself, various conversion technologies are necessary to obtain high-value products. In this chapter, physical, chemical, and biochemical conversion technologies will be described briefly. Compared with physical and chemical conversion technologies, biochemical conversion technology shows more advantages, which should be studied further for multidirectional utilization of biomass.