Ore grinding and grading method for complex and easily-argillized ore

The invention provides an ore grinding and grading method for complex and easily-argillized ore, which comprises the following steps: feeding a product after ore crushing into a first-section ball mill for ore grinding, feeding ore discharged by the first-section ball mill into a first-section hydrocyclone for grading through a slurry pump, feeding settled sand of the first-section hydrocyclone into a second-section ball mill, and feeding the settled sand into a third-section ball mill; grading overflow of the first-section cyclone and grading overflow of the second-section cyclone are converged for flotation; and the settled sand of the first-stage cyclone and the settled sand of the second-stage cyclone converge and enter a second-stage ball mill for ore grinding, ore discharged by the second-stage ball mill returns to the second-stage cyclone for classification, and overflow enters a flotation process. According to the method, first-stage cyclone classification is conducted through the first cyclone after