Negative-pressure dust removal system and device for movable unloading on ore tank

The invention discloses a negative-pressure dust removal system and device for movable unloading on an ore tank, and solves the problems that an existing dust removal device cannot remove overflow dust away from an opening of an unloading chute, the dust removal effect is not ideal in the use process, obvious raised dust can be seen in a plant, the raised dust is particularly obvious when an unloading trolley moves in a bin, and the dust removal effect is bad. The dust removal device comprises an unloading trolley, a lifting switching valve, a bucket elevator and a dust storage bin; when the unloading trolley moves to a parking point of a certain ore tank for production and unloading, the lifting switching valve on a negative-pressure dust suction cover of the ore tank is opened; when the unloading trolley stops unloading or moves to a fixed parking unloading point of the next ore tank for unloading, the lifting switching valve on the negative-pressure dust suction cover of the ore tank is delayed until no ov