Abstract: Preparation of nuclear power grade UO₂ by TBP solvent extraction technology is studied using impure uranium concentrate as raw material. In the uranium concentrate pretreated, the moisture is reduced effectively, and organic impurity is removed, forms of impurities easy to generate colloid are rectified. Uranium can be extracted from water phase of uranium mass concentration 300-400 g/L using φ=30%TBP-kerosene as organic phase. The impurities in loaded organic phase are removed out in two stage scrubbing. Uranium in loaded organic phase is stripped using dilute nitric acid. High purity uranyl nitrate solution can be obtained. After precipitating, transfer crystallization and calcinning, nuclear power grade UO₂ is produced.