An automated nucleic acid extraction device, comprising: a base body comprising a sample accommodating area, a column accommodating area comprising a sample tip accommodating space and a column tip accommodating space, a cassette accommodating area and a collection tube, wherein the sample accommodating area, the column accommodating area, the cassette accommodating area and the collection tube are arranged in a linear direction; a sample tip and a column tip each comprising an abutting portion, wherein the sample tip and the column tip are movably disposed in the sample tip accommodating space and the column tip accommodating space, respectively; a cassette arranged in the cassette accommodating area, wherein the cassette includes two parallel outer walls and at least four vertical walls, the outer walls are arranged on the base body vertically, each of the vertical walls is arranged between the outer walls and two sides of each of the vertical walls are connected to the outer walls, respectively, the vertical walls divide a space between the outer walls to jointly form a lysis buffer well, at least one wash buffer well and an elution buffer well, each of the vertical walls forming the lysis buffer well, the at least one wash buffer well and the elution buffer well includes a load-bearing abutment, the lysis buffer well, the at least one wash buffer well and the elution buffer well are arranged in the linear direction, and the load-bearing abutment is provided with a vertical arcuate wall having an arc angle greater than or equal to 90 degrees or a vertical polygonal wall comprising at least two vertical supporting walls (3142, 3143), wherein an included angle between the supporting walls (3142, 3143) is less than 180 degrees; a driving unit arranged on the base body; a moving frame arranged on the base body vertically and driven by the driving unit to reciprocate in the linear direction; and a syringe arranged on the moving frame and being moved along with the moving frame, wherein the syringe is detachably connectable to the sample tip or the column tip, wherein the driving unit drives the moving frame and the moving frame carries the syringe, causing the syringe to move to the sample accommodating area, the column accommodating area, the cassette accommodating area and the collection tube, wherein the abutting portion of the sample tip or the column tip is configured to be abutted against the load-bearing abutment of each of the vertical walls when the syringe is connected to the sample tip or the column tip and the driving unit has moved the syringe with the moving frame to the cassette. a base body comprising a sample accommodating area, a column accommodating area comprising a sample tip accommodating space and a column tip accommodating space, a cassette accommodating area and a collection tube, wherein the sample accommodating area, the column accommodating area, the cassette accommodating area and the collection tube are arranged in a linear direction; a sample tip and a column tip each comprising an abutting portion, wherein the sample tip and the column tip are movably disposed in the sample tip accommodating space and the column tip accommodating space, respectively; a cassette arranged in the cassette accommodating area, wherein the cassette includes two parallel outer walls and at least four vertical walls, the outer walls are arranged on the base body vertically, each of the vertical walls is arranged between the outer walls and two sides of each of the vertical walls are connected to the outer walls, respectively, the vertical walls divide a space between the outer walls to jointly form a lysis buffer well, at least one wash buffer well and an elution buffer well, each of the vertical walls forming the lysis buffer well, the at least one wash buffer well and the elution buffer well includes a load-bearing abutment, the lysis buffer well, the at least one wash buffer well and the elution buffer well are arranged in the linear direction, and the load-bearing abutment is provided with a vertical arcuate wall having an arc angle greater than or equal to 90 degrees or a vertical polygonal wall comprising at least two vertical supporting walls (3142, 3143), wherein an included angle between the supporting walls (3142, 3143) is less than 180 degrees; a driving unit arranged on the base body; a moving frame arranged on the base body vertically and driven by the driving unit to reciprocate in the linear direction; and a syringe arranged on the moving frame and being moved along with the moving frame, wherein the syringe is detachably connectable to the sample tip or the column tip, wherein the driving unit drives the moving frame and the moving frame carries the syringe, causing the syringe to move to the sample accommodating area, the column accommodating area, the cassette accommodating area and the collection tube, wherein the abutting portion of the sample tip or the column tip is configured to be abutted against the load-bearing abutment of each of the vertical walls when the syringe is connected to the sample tip or the column tip and the driving unit has moved the syringe with the moving frame to the cassette.