The utility model discloses a foraminiferous damping sound insulation sleeve for power capacitor, including capacitor unit, capacitor unit includes the capacitor unit top face of right -hand member and the capacitor unit bottom face of left end, capacitor unit top off -plate side be provided with a sleeve just or the capacitor unit bottom face outside be provided with end sleeve, top sleeve and capacitor unit top face are provided with the head space chamber, be provided with end cavity between end sleeve and the capacitor unit bottom face, top sleeve and end sleeve all are provided with a plurality of balanced hole, and the balanced hole constitutes the intercommunicating pore of head space chamber or end cavity and outside air. Set up the balanced hole on the sleeve, air and outside air in the intercommunication cavity to sleeve that the inflation of having eliminated the cavity air results in with the shrink comes off or reduces the problem of (eliminating even) from the condenser, has stablized telescopic long -term the noise reduction effect, has solved the ventilation cooling problem that the condenser was wrapped up the terminal surface simultaneously.