The invention relates to a heavy load battery box. Transferring of the battery box between a vehicle battery bin and a support battery bin is achieved through a telescopic arm of a robot. The battery box comprises a box body, a first installing piece, a second installing piece, a supporting piece and electrical connectors, wherein the first installing piece and the second installing piece protrude out of the two opposite sides of the box body and are used for being arranged in the vehicle battery bin or the support battery bin, the supporting piece protrudes out of the two opposite sides of the box body and is used for being arranged in the supporting piece of the telescopic arm, and the electrical connectors are installed on the box body. The battery box is installed on the vehicle battery bin or the support battery bin through the first installing piece and the second installing piece, gravity of the battery box is transmitted to the vehicle battery bin or the support battery bin through the first installing piece and the second installing piece, the telescopic arm extends into the vehicle battery bin or the support battery bin and makes contact with the supporting piece so as to have bearing and carrying effects on the battery box directly, limitations of size and position conditions are eliminated, so that the telescopic arm can directly drive the battery box to smoothly enter and exit from the support battery bin and the vehicle battery bin, and replacement of the battery box is convenient.