System for preventing numerical control machining center tool from being polluted during exchange

The invention discloses a system for preventing a numerical control machining center tool from being polluted during exchange. The system comprises a tool exchange device and a cleaning device, wherein the tool exchange device is arranged between a main shaft and a tool magazine; the cleaning device is arranged at one side, far away from the tool exchange device, of the main shaft, and the cleaning device comprises a bottom plate fixed to the main shaft; a guide rod parallel to the axis of the main shaft is arranged on the bottom plate; a sliding block capable of sliding along the guide rod is arranged on the guide rod; a cleaning nozzle is arranged on the sliding block; an air curtain nozzle is arranged at the position, close to a tool hole of the main shaft, of the bottom plate; a lifting block is arranged on the tool exchange device; and the tool exchange device drives the sliding block to move relative to the axis of the main shaft through the lifting block. The cleaning device can automatically move acco