The invention discloses a method for co-production of feed manganese sulfate by using wastewater of crude indium production. According to the method, on the basis of production of feed manganese sulfate through a wet method, the influence of excessive sulfuric acid and heavy metals including arsenic, cadmium and the like in the wastewater of the crude indium production through a wet method on the environment is thoroughly eliminated while the feed manganese sulfate is produced, so that the production of crude indium and the feed manganese sulfate through the wet method achieves comprehensive and full utilization of wastes, and the pollution caused by waste acid water containing heavy metals to the environment is thoroughly eliminated. The method comprises the steps of 1, performing leaching reaction on manganese ash in a leaching tank by using indium preparation wastewater; 2, performing pressure filtration; 3, adjusting the pH value of the filtrate to 4-4.5, and then pressing liquid; 4, adding barium sulfide to improve the pH value of a stock solution to 5-5.4, and then filtering; 5, cooling and standing the stock solution, adding an SDD (sodium dimethyl dithiocarbamate) solution and a flocculating agent, then performing pressure filtration, concentrating the filtrate, performing evaporative crystallization, and drying to obtain a feed manganese sulfate product. By adopting the method, the indium preparation wastewater and waste residues causing environmental pollution can be fully and comprehensively used, and a raw material for producing manganese sulfate is provided, so that the method is favorable for reducing the production cost and protecting the ecological environment.