The inevitable crystal growth of Cr2O3 during sintering causes the generation of cracks, which degrades the high-temperature properties. To solve this, SiO2 is adopted as the second phase and the specimens are sintered at 1200-1500 degrees C under buried carbon condition. The results show that the addition of approximate 20wt% SiO2 can effectively control the crystal growth of Cr2O3. The Cr2O3 particle size can keep uniform ranging from 4m to 12m even when the temperature increases to 1500 degrees C. The sintering of Cr2O3 mainly follows the defect model, which depends on the reaction temperatures and atmospheres. This work should also contribute to the sintering of other oxide refractories with controlled crystal size for practical application.