A whole process continuous gas-assisted magnetic separation system, wherein it comprises an adsorption tank, the adsorption tank is connected with an extraction column, and the extraction column is connected with a desorber; the extraction column comprises a hollow air flotation column, a mixed liquid inlet and a raffinate outlet are arranged on the air flotation column, the mixed liquid inlet is connected with a mixed liquid outlet, and a gas inlet is arranged at the bottom of the air flotation column; the desorber comprises a hollow air flotation column, a magnetic particle inlet and a product outlet are arranged on the air flotation column, and the magnetic particle inlet is connected with a mixture storage tank, a magnetic roller is arranged at the top of the air flotation column, a scraper is arranged on one side of the magnetic roller, a magnetic particle storage tank is arranged at the end of the scraper, the magnetic particle storage tank is connected with the adsorption tank, and a gas inlet is arranged at the bottom of the air flotation column; characterized in that a feed liquid inlet and a magnetic particle inlet are arranged at the top of the adsorption tank, a mixed liquid outlet is arranged at the bottom of the adsorption tank, and a stirring device is arranged inside the adsorption tank, wherein in the hollow air flotation column of the extraction column, a magnetic roller is arranged at the top of the air flotation column, a scraper is arranged on one side of the magnetic roller, a mixture storage tank is arranged at the end of the scraper, wherein the air flotation columns of the extraction column and the desorber are connected with a washing device, and the washing port of the washing device is arranged opposite to the scraper, wherein peristaltic pumps are arranged between the adsorption tank and the extraction column, between the extraction column and the desorber and between the washing device and the scraper, wherein the flow rate of the peristaltic pump is adjusted in a range of 3 to 6800 mL/min, wherein a gas supply line is connected with the gas inlets of the extraction column and the desorber, respectively, wherein gas flowmeters are arranged at the gas inlets of the extraction column and the desorber, wherein the measurement range of the gas flowmeter is set at 6 to 60 L/h; and wherein the magnetic rollers of the extraction column and the desorber comprise a magnetic arc region, and the arc of the magnetic arc region is 240°, and a certain amount of small-size rubidium ferroboron rare earth permanent magnets are arranged in an annular shape at a certain distance along the surface of the magnetic rollers. the extraction column comprises a hollow air flotation column, a mixed liquid inlet and a raffinate outlet are arranged on the air flotation column, the mixed liquid inlet is connected with a mixed liquid outlet, and a gas inlet is arranged at the bottom of the air flotation column; the desorber comprises a hollow air flotation column, a magnetic particle inlet and a product outlet are arranged on the air flotation column, and the magnetic particle inlet is connected with a mixture storage tank, a magnetic roller is arranged at the top of the air flotation column, a scraper is arranged on one side of the magnetic roller, a magnetic particle storage tank is arranged at the end of the scraper, the magnetic particle storage tank is connected with the adsorption tank, and a gas inlet is arranged at the bottom of the air flotation column; characterized in that a feed liquid inlet and a magnetic particle inlet are arranged at the top of the adsorption tank, a mixed liquid outlet is arranged at the bottom of the adsorption tank, and a stirring device is arranged inside the adsorption tank, wherein in the hollow air flotation column of the extraction column, a magnetic roller is arranged at the top of the air flotation column, a scraper is arranged on one side of the magnetic roller, a mixture storage tank is arranged at the end of the scraper, wherein the air flotation columns of the extraction column and the desorber are connected with a washing device, and the washing port of the washing device is arranged opposite to the scraper, wherein peristaltic pumps are arranged between the adsorption tank and the extraction column, between the extraction column and the desorber and between the washing device and the scraper, wherein the flow rate of the peristaltic pump is adjusted in a range of 3 to 6800 mL/min, wherein a gas supply line is connected with the gas inlets of the extraction column and the desorber, respectively, wherein gas flowmeters are arranged at the gas inlets of the extraction column and the desorber, wherein the measurement range of the gas flowmeter is set at 6 to 60 L/h; and wherein the magnetic rollers of the extraction column and the desorber comprise a magnetic arc region, and the arc of the magnetic arc region is 240°, and a certain amount of small-size rubidium ferroboron rare earth permanent magnets are arranged in an annular shape at a certain distance along the surface of the magnetic rollers.