Abstract: The system defines an assembly formed by a truck with a compacting box of wastes and handling crane (3) of a receptor container, and containing the wastes assigned to be compacted, the compacting is carried out by a displaceable wall in the inside of compacting box, the crane (3) including a hooking device (12) of the container in order to place this one facing the upper loading door (7) of the compacting box (2), as well as a mechanism (16) to produce the opening of the corresponding unloading gates foreseen to such effect in the container (4) itself, when the hooking device (12) reaches the stop (13) in its displacement over the crane boom, the unloading gates (17) ot the container (4) being closed automatically when the hooking device (12) is in any other position over the crane boom.