The invention discloses a method for refining a magnesium chloride solution. The method comprises the steps of A), providing the magnesium chloride solution in which coarse crystallization magnesium chloride is dissolved; B), adjusting the pH value of the magnesium chloride solution to be 4-5 and enabling SiO32 in the magnesium chloride solution to form a silicic acid gel and then adding sodium sulphide and barium chloride in the magnesium chloride solution to generate ferrous sulfide sediment and barium sulfate sediment; C), filtering the magnesium chloride solution by using a membrane filtration element to obtain filter liquor; and D), absorbing boron in the filter liquor by using resin to obtain the refined magnesium chloride solution. According to the method for refining the magnesium chloride solution, the steps of magnesium chloride solution refining can be simplified and the refining process of the magnesium chloride solution can be shortened.