The utility model discloses a dehumidification system for high tension switchgear, all be equipped with the actuating sleeve in switch brake sword and grounding switch blade's the pivot, be equipped with the first baffle that divide into the appearance chamber of actuating sleeve three cavity in the actuating sleeve, second baffle and third baffle, the contained angle that first baffle and secondbaffle formed is less than 180 and is greater than 90, set up first exhaust hole and second exhaust hole along the axis symmetry of actuating sleeve on the actuating sleeve bottom surface, set up first arc air inlet duct on the corresponding actuating sleeve lateral wall of cavity that first baffle and third baffle formed, set up second arc air inlet duct on the corresponding actuating sleeve lateral wall of cavity that first baffle and second baffle formed, the radian of first arc air inlet duct and second arc air inlet duct all is greater than 90, the inlet port centre of a circle is greaterthan 90 to the radian of the second exhaust hole circle heart, the utility model provides a through this internal humidity signal of humidity transducer receive switch cabinet, centrifugal fan startsa dehumidification system for high tension switchgear to this internal automatic dehumidification of cubical switchboard.