Disclosed is a solid oxide fuel cell bundle, including a plurality of fuel cells each having a polygonal tubular support an outer surface of which has a plurality of planes, an outer connector formed on one plane among the plurality of planes of the tubular support, a plurality of unit cells respectively formed on two or more remaining planes of the tubular support except for the one plane, and inner connectors for connecting the unit cells and the outer connector in series, wherein the fuel cells is connected in series in such a manner that the outer connector of a fuel cell is bonded to the unit cell of an additional fuel cell, and the unit cells are connected in series, thus exhibiting excellent cell performance and high power density per unit volume, and maintaining high voltage upon collection of current to thereby reduce power loss due to electrical resistance.