The utility model discloses a dismounting special tool for an SF6 gas pressure sensor. The dismounting special tool comprises a hollow circular steel bar accommodating groove with a base; the key point is that the accommodating groove takes a circular cup body shape; a groove mouth is formed in the front side surface of the accommodating groove; screw holes matched with bolts are formed in the two side surfaces of the accommodating groove respectively; a fixing rod is arranged at the lower part of the base of the accommodating groove; a sexangular bolt head is arranged at the lower end of the fixing rod. The dismounting special tool has the benefits that dismounting and fastening time of the SF6 gas pressure sensor is remarkably shortened, the security risk is reduced, the working efficiency is improved, the fastening effect is favorable, no mechanical damage is generated to the sealing surface of the sensor; the dismounting special tool has the characteristics that the structure is simple and the processing is convenient; the dismounting special tool is solid and durable as well as low in the manufacturing cost.