Performance test system and test method for centrifugal compressor

The invention relates to the technical field of compressors, in particular to a performance testing system and method for a centrifugal compressor, the performance testing system comprises a controller, a two-stage compressor, an energy balancer and a mixer, and the energy balancer is connected with a cooling water inlet pipeline and a cooling water outlet pipeline; the two-stage compressor comprises a low-pressure-stage compressor and a high-pressure-stage compressor which are connected in series, gas exhausted by the high-pressure-stage compressor enters a liquid space of the energy balancer and generates saturated gas, the saturated gas in the energy balancer enters the mixer, and one part of saturated liquid in the energy balancer enters the mixer; the other part of the liquid supply pipeline cools the motor and generates overheated gas, the overheated gas enters the mixer, and an outlet of the mixer is connected with an inlet of the low-pressure-stage compressor. The whole structure is simplified, the en