The invention discloses a process for resourceful treatment of high-salt wastewater containing magnesium. The process comprises the following steps: (1) classifying and collecting high-salt mother liquor wastewater which has magnesium ions and is produced in a dye production process to carry out suction filtration and recycle a dye intermediate or a dye product; (2) adjusting pH value to be 3.0-6.0 and adding powder active carbon to carry out suction filtration; (3) adding sodium hydroxide till the pH value of the high-salt wastewater to be 10.0-11.0 and adding a flocculating agent to flocculate, settle and centrifugally separate; (4) converting magnesium hydroxide to light magnesium oxide through a self-control program in an industrial microwave oven under a heating condition, crushing and grinding the light magnesium oxide to prepare powder light magnesium oxide; (5) processing a clear liquor obtained in the step (3) by using a nanofiltration membrane to obtain a sodium salt solution and reuse the sodium salt solution in a production process. The intermediate high-salt mother liquor wastewater generated in the disperse dye production process is processed by a series of processes of removing COD, decolorizing, carrying out microwave treatment and membrane treatment, so that the waste liquid is recycled, thus realizing zero discharging of the wastewater.