The invention relates to a portable outward transport box for a relay protection instrument. The box comprises a first box body for containing the relay protection instrument, wherein an upward opening type cover plate is arranged at the top of the first box body. The box is characterized in that a second box body with the height about 1/2 that of the first box body is further arranged on one side of the first box body, an upward opening type cover plate is further arranged at the top of the second box body, and the first box body is integrally connected with side plates and a bottom plate of the second box body; a telescopic pull rod is arranged on the other side, opposite to the second box body, of the first box body, and the height of the telescopic pull rod telescoped to the lowest state is about twice that of the first box body; two castors are arranged below the telescopic pull rod and in connection positions of side plates and a bottom plate of the first box body. Compared with the prior art, the box has the advantages that purposes of the box can be achieved, the labor efficiency is improved, the labor intensity is reduced, and the condition that tools or stepladders are forgotten is completely eradicated.