The invention discloses a saline-water refining device and method capable of directly removing calcium and magnesium. The saline-water refining device comprises a separation film, wherein multiple micron channels in the same orientation are formed in the separation film, the diameters of the micron channels are 10-100 microns, a stock solution region communicated with inlet ends of the micron channels is arranged on one side of the separation film, and a separation region connected with outlet ends of the micron channels is arranged on the other side of the separation film; a section of anion exchange membrane is arranged on the inner wall of each micron channel, and the outer surfaces of the anion exchange membranes are communicated with inner cavities of the micron channels; and a first electrode is arranged on one side, opposite to the stock solution region, of the separation film, a second electrode is arranged on one side, opposite to the separation region, of the separation film, the first electrode and the second electrode are used for generating field intensity covering the field intensity directions of the micron channels from the separation region to the stock solution region, and third electrodes are arranged on the anion exchange membranes. The saline-water refining device has the advantages that only a hundred-micron-order aperture is required, and the operational pressure and the manufacturing difficulty are reduced, so that the separation cost is lowered, and the industry promotion is improved.