In order to investigate the effects of recycling NaOH as reaction medium on the oxidative decomposition process of chromite ore, aqueous NaOH solution saturated with Na2CrO4 at 90℃, instead of single aqueous NaOH solution, was chosen as the reaction medium and the effects of alkali concentration, oxygen partial pressure, particle size of chromite ore powder, reaction temperature and reaction time on the chromite decomposition process were systematically investigated. The results showed that, the extraction rate of chromium could reach as high as 95.24% after 240 min at 250℃ with NaOH mass concentration of 50wt%, oxygen pressure of 3.2 MPa and partial size less than 48 μm. As far as the separation efficiency of chromium from alkali and impurities was also considered, about 96.36% of the chromium extracted from the chromite ore was found in the mixed solids of chromite ore processing residue (COPR) and sodium chromate crystal, while 84.92% of aluminum and 95.04% of silicon extracted from chromite ore was found in the leaching liquor of chromite ore under the better process conditions. At the same time, 89.41% of the unreacted NaOH, was found in the leaching liquor of chromite ore. Compared with the original method with single NaOH as the reaction medium, the new reaction mode in this work enabled the main element of chromium from the chromite ore, the impurities of aluminum and silicon from the chromite ore, and the unreacted NaOH to distribute respectively into the leaching liquor of COPR and crystal mixture, and the leaching liquor of chromite ore, therefore achieving a high separation efficiency. It solved the problems of separation of chromium from alkali and impurities in the leaching liquor of chromite ore and leaching liquor of COPR and crystal mixture in the oxidative decomposition process of chromite ore.