Centrifugal compressor vane diffuser

The utility model relates to a centrifugal compressor vane diffuser comprising a centrifugal impeller, a centrifugal compressor case and a diffuser. Key points of the centrifugal compressor vane diffuser include that jet nozzles with adaptors are uniformly disposed on the circumference with an R radius at an outlet position of the centrifugal compressor case; the centrifugal compressor case equipped with the jet nozzles is integrally connected with an outer case of the diffuser through bolts. The centrifugal compressor vane diffuser has simple structure, convenient installation and low manufacturing cost. By using external air source or high pressure gas at an outlet of the compressor to blow to the front edges of radial diffuser vanes via the jet nozzles, inlet airflow condition of the radial diffuser can be improved, airflow angle of attack near stall can be reduced, and airflow is hard to be separated, thereby increasing total pressure recovery coefficient of the diffuser, and surge margin and stable work