The invention discloses a supercritical water oxidation (SCWO) system which can eliminate odor at a same time. According to the system, a compartment is used for collecting waste gas near organic wastewater. An air compressor is arranged in the system. An air outlet pipe of the air compressor is connected with an air inlet of a supercritical water oxidation reaction kettle. A water outlet pipe of a wastewater tank is connected with a water inlet of the supercritical water oxidation reaction kettle. A water outlet pipe of the supercritical water oxidation reaction kettle is connected with a water inlet of a heat exchanger. A water outlet pipe of the heat exchanger is connected to a water inlet of a return water heater. A waste gas discharge port, a water discharge port, a cooling circulation water inlet pipe and a cooling circulation water outlet pipe are arranged on the return water heater. The cooling circulation water inlet pipe and the cooling circulation water outlet pipe are respectively connected with a cooling circulation water outlet and a cooling circulation water inlet of a cooling reflux device. According to the invention, with a gas collection device in the system compartment, waste gas is introduced into the supercritical reaction kettle. While organic pollutants in wastewater is degraded with high efficiency, organic in waste gas is effectively removed. The operation is automatic. The system is energy-saving and emission-reducing, and has the advantages of low cost and simple structure.