Abstract: A supercritical carbon dioxide (S-CO₂) Brayton cycle system is a new type of energy system with broad application prospects. A S-CO₂ compressor is the core component of the system, which has an important influence on the operation of the system. This paper introduces the design of the S-CO₂ centrifugal compressor, builds a hundreds kilowatt level test system of the S-CO₂ compressor, and carries out the establishment test of supercritical state of CO₂ at the compressor inlet, the compressor performance test and the compressor inlet state control test. The test results show that the compressor can run in the maximum speed (40000 r/min), wide working condition and supercritical state, and the test maximum pressure ratio reaches 1.34. The stability control of the compressor inlet state is realized well. When the speed is 9000r/min and 20000r/min, the fluctuation of inlet pressure is less than 0.12MPa, and for inlet temperature, less than 1℃. The test results are of great significance for S-CO₂ compressor design and S-CO₂ Brayton circulation system level control strategy research.