The invention discloses a method for resource utilization of wastewater in the synthetic process of battery-grade iron phosphate. The method comprises the following steps: a, adding ammonia water to adjust the pH value of the wastewater generated in the synthetic process of the iron phosphate to 7-8 to obtain a solution; b, filtering the solution for multiple times to obtain a product, namely a filtrate without suspended solids; c, pumping the filtrate into an ultrahigh-pressure reverse osmosis device, and performing a reaction to obtain concentrated water A and fresh water A; d, introducing the concentrated water A into an MVR evaporative crystallization device, carrying out vacuum concentration evaporative crystallization to obtain an ammonium sulfate and monoammonium phosphate mixture and evaporation condensate water, and carrying out centrifugal separation on the ammonium sulfate and monoammonium phosphate mixture to respectively obtain ammonium sulfate and monoammonium phosphate;e, mixing the fresh water A and the evaporation condensate water, and pumping the mixed water into a primary reverse osmosis device to obtain concentrated water B and fresh water B; and f, pumping theconcentrated water B into an ultrahigh-pressure reverse osmosis device, and recovering the fresh water B. The method has the beneficial effect that the treatment cost of the wastewater can be saved.