The invention relates to a method for comprehensive utilization of high-iron red mud, wherein the method includes the following steps: S1, deironing the high-iron red mud, then mixing and batching thedeironed high-iron red mud with lime, an alkali and recycling mother liquor, and after slurry is prepared, drying outside a kiln; S2, carrying out sintering reaction of the dried raw material at lowtemperature to obtain a sintered clinker; S3, carrying out leaching reaction of the sintered clinker, filtering, and carrying out liquid-solid separation to obtain a leached residue and a leached solution; S4, treating the leached solution, selecting crystal seed decomposition, carbonation decomposition or evaporative crystallization process according to specific needs, or freely combining, requiring to adjust a solution obtained from the reaction, and allowing the solution to return to the mixing process; and S5, carrying out dealkalization reaction of the leached residue under the action ofa sodium hydroxide solution, and carrying out liquid-solid separation, to obtain calcium silicate powder and a dealkalization solution, wherein a part of the dealkalization solution is used as the products, and a part of the dealkalization solution returns for dealkalization. By the method, the high-iron red mud is completely recovered, and a series of products containing aluminum, iron products and the calcium silicate powder material are prepared. The method can largely decompose the high-iron red mud, realizes the recovery and value-added utilization of the high-iron red mud, and achieves the effect of green utilization of resources.