The invention relates to oxide dispersion-strengthening ferrite steel with a bicrystal structure, compirisng the following components of Cr, W, Ti, Y2O3 and the balance of Fe. A preparation method of the oxide dispersion-strengthening ferrite steel with the bicrystal structure comprises the following steps of: uniformly mixing Fe-Cr-W prealloy powder and ball milled powder according to a certain proportion; placing the mixed powder into a steel capsule for degassing and seal welding; then thermally canned-forging, solidifying and molding; and carrying out thermal treatment. The ferrite steel with excellent mechanical property at room temperature and high temperature can be produced through mixing powders in different proportions and controlling on solidifying and molding as well as the following thermal treatment. Oxide dispersion-strengthening alloy produced by the invention has the characteristic of the bicrystal structure, and the structure can simultaneously give the alloy higher strength and excellent toughness. The efficiency for producing the oxide dispersion-strengthening ferrite steel can be increased effectively, the process cost can be greatly saved, and the oxide dispersion-strengthening ferrite steel is beneficial to industrial production.