Abstract:：In order to improve the leaching rate of uranium in a sulfur-carbonate uranium ore and control the oxidation leaching rate of pyrite, the influence of particle size, temperature, sodium carbonate content and air partial pressure on the leaching rate of pyrite and uranium was investigated. The results showed that when the leaching temperature, alkali dosage, oxygen partial pressure and particle size were 150℃,16%,0.7 mpa and 74μm, the leaching rate of pyrite and uranium was 23.63% and 81.61%, respectively, which was higher than 7.27% in the process of alkali leaching at atmospheric pressure, and the leaching rate of pyrite was controlled at about 3.8% without obvious increase. Among them, temperature, amount of sodium carbonate and particle size have the most significant effect on pyrite leaching, and air partial pressure and particle size have the most significant effect on uranium leaching.