The SCWO supercritical water oxidation device mainly consists of the feeding system, reaction system, salt‑removal system, cooling system and control system. The main process flow is as follows: sewage and oxidant are pressurized separately and mixed in the jet mixer to form mixed materials. The mixed materials are preheated by the preheater and then fed into the reaction system for reaction. The high‑temperature products generated from the reaction go through waste heat recovery and are then cooled in the cold‑water tank. Subcritical water is introduced into the subcritical salt‑water tank. Precipitated salts enter the subcritical salt‑water tank, flow into the salt‑water flash tank in the form of subcritical salt‑water to obtain solid salts, while the flashed high‑temperature gas is cooled in the cooling system.