The present invention relates to the preparation process of ferric oxide red powder. Unlike available technology, which has the demerits of high production cost and low product purity of processed ferrous permanganate, the present invention uses ferrous sulfate as the side product of titanium white powder production as material and produces high purity ferric oxide red powder via purification to eliminate impurity, precipitation to eliminate manganese, water washing, spray burning and other steps. The ferric oxide red powder has impurity content of Si, Al, Ca, Mg, etc. less than 80 ppm, Mn content lower than 0.2 wt% and Fe2O3 content over 99.5 wt%, and is used as soft magnetic material. The present invention has simple technological process, low production cost and high product quality, and may be used in industrial production.