The invention discloses a clamping and electricity-conducting device for an auxiliary electrode of a vacuum arc remelting furnace. A pneumatic chuck is arranged at the lower end of a thrust rod; a conductive rod is arranged inside the thrust rod; a conductive head is arranged at the lower end of the pneumatic chuck and is connected to the lower end of the conductive rod; an insulation sleeve is arranged on the outer side of the thrust rod and the outer side of the pneumatic chuck, and a pneumatic jacket is arranged outside the insulation sleeve; steel balls are embedded into holes of the pneumatic jacket, the insulation sleeve is arranged between the pneumatic jacket, the thrust rod and the pneumatic chuck, and a detection ring is arranged at the neck part in the middle of the pneumatic jacket. The clamping and electricity-conducting device for the auxiliary electrode is moved to the part right above the auxiliary electrode, an operation air cylinder pulls back the pneumatic chuck, and then the steel balls are retracted; the clamping and electricity-conducting device for the auxiliary electrode is inserted into a hole in the upper end of the auxiliary electrode, the detection ring is pushed upwards, the operation air cylinder moves for pushing out the pneumatic chuck after the detection ring reaches the position, the steel balls are pushed out, and then the clamping and electricity-conducting device for the auxiliary electrode is vertically lifted. The clamping and electricity-conducting device has the advantages that the electrical conductivity is good, the strength of clamping the auxiliary electrode is high, and the service life is long.