The invention belongs to the field of resource-oriented utilization of chemical wastes, and particularly relates to a resource-oriented utilization method of waste concentrated sulfuric acids. The method disclosed by the invention comprises the following steps: firstly, enabling magnesite light-calcined powder as a medium to react with a high-concentration waste sulfuric acid, so that magnesium sulfate is obtained; secondly, calcining the magnesium sulfate at a high temperature so as to remove organic matters, carrying out leaching separation on the obtained product so as to obtain a magnesium sulfate solution, and sequentially carrying out evaporation and concentration, cooling crystallization and dried dehydration on the magnesium sulfate solution so as to obtain a magnesium sulfate product; and finally, absorbing sulfur dioxide produced by high temperature calcination by using magnesite light-calcined powder and leaching slag so as to generate magnesium sulfite, and then converting the magnesium sulfite into magnesium sulfate through air oxidation; the magnesium sulfate product can be applied to the production of compound fertilizers; in the whole system, only a flue gas absorption part produces a small amount of silicon and calcium containing slag which can be used as raw materials of cement or building materials; and organic matters in organic matter containing high-concentration waste sulfuric acids are utilized as heat. According to the invention, the clean, efficient and comprehensive utilization of high-concentration waste sulfuric acids can be realized, therefore, the method is a green and clean resource-oriented utilization method of high-concentration waste sulfuric acids.