Supposing that all the biogas generated from anaerobic digestion of the hydrothermally pretreated CPCAR is combusted to generate steam, the HTPT step consumes only about 50% of the produced steam. This means that the entire process can output 1.38 t steam (or 111 Nm3 methane) for treating 1 t CPCAR on dry weight basis. The result demonstrates that the proposed process for treating antibiotic residue does not require additional energy, exhibiting a promising prospect for solving the high-energy consumption problem met in treating high-water antibiotic residues. In practical hydrothermal treatment process, the energy consumption would be rather lower by recovering the excess heat of exhaust steam to preheat the raw residue, which can further reduce the steam consumption to 0.109 t steam for HTPT of 1 t CPCAR (according to conventional method, 0.130 t steam for HTPT of 1 t CPCAR), and correspondingly 1.75 t steam (or 140 m3 methane) could be output for treating one tone of CPCAR on dry weight basis. This is undoubtedly of vital importance for reducing energy consumption in engineering practice.