The invention relates to small-gap superconductor cavity inner surface high-pressure flushing equipment. The equipment is characterized by comprising a support frame, an upper support tabletop, a rotating platform, a spraying rod, a platform driving device, a spraying rod driving device, a high-pressure diaphragm pump and a control system; the top of the support frame is fixedly connected to the upper support tabletop; the rotating platform is arnged at the top of the upper support tabletop; first through holes for a reciprocating motion of the spraying rod are formed in the centers of the support frame and the upper support tabletop; a second through hole for the reciprocating motion of the spraying rod is formed in the center of the rotating platform; guide sleeves for positioning and supporting the spraying rod are arranged in the first through hole and the second through hole in the upper support tabletop; a nozzle is arranged at the top of the spraying rod; the bottom of the spraying rod is connected with the high-pressure diaphragm pump; the platform driving device and the spraying rod driving device are arranged on the support frame; and the high-pressure diaphragm pump, theplatform driving device and the spraying rod driving device are electrically connected with the control system. The equipment can be widely applied to the technical field of accelerator manufacturing.