Waste Camellia oleifera Shells (WCOSs) have potential to produce sustainable, dean, green energy sources. In this paper, hydrothermal carbonization (HTC), torrefaction, and pyrolysis were applied to investigate the characterization of three types Of biochar from., WCOSs. The biochars were analyzed with ultimate analysis, proximate analysis, hydrophobicity, Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), scanning electron microscopy, and Fourier transform infrared spectroscopy (FTIR). The results showed that the biochars were able to replace the lignite or semi-anthracite coal because of the higher calorific value. In comparison to raw WCOSs, the BET characteristics and hydrophobicity of the biochars were improved by thermochemical processes. Evolutions of WCOSs under different conditions, as determined by FTIR and XRD, showed that hemicelluloses and cellulose were decomposed through HTC, torrefaction, and pyrolysis) while the degradation of lignin occurred through pyrolysis. In addition, combustion behaviors of WCOSs and their biochars were significantly different.