The invention relates to a PACK in-box auxiliary system. The auxiliary system comprises a plastic handle; the plastic handle is fixedly connected with a main board located below through screws; a buffer is mounted on a position close to the central position of the main board; the buffer is perpendicularly downward corresponding to the main board; guiding shafts are mounted below four opposite angles of the main board respectively; the guiding shafts are fixedly connected with the main board through magnetic attraction heads; through holes corresponding to the guiding shafts are formed in a battery box body below the guiding shafts; two groups of hook holes are formed in the two side outer walls of the battery box body respectively; and a transporting mechanism is arranged above the batterybox body. Compared with the prior art, the auxiliary system has the advantage that batteries are mounted to fixed point stations in a perpendicularly stacked manner from the aspect of the structure;and in the common battery in-box operation by manpower, the visual angle of an operator is shielded by the batteries, which causes battery malposition or displacement phenomena easily; and consequently, the phenomenon of short circuit in final welding is caused.