In order to study the effect of fused corundum content on properties of silicon-based ceramic cores, the ceramic cores with different amount of fused corundum(0%~30%) were prepared by the hot injection method, where quartz glass powder was used as raw materials, fused corundum as mineralizer, and the ceramic casting wax as the plasticizer. The results showed that with the increase of fused corundum, the shrinkage of the samples increased gradually, the porosity decreased at first and then increased, resulting in the higher degree of densification, while the flexural strength and high temperature creep resistance were falling after firstly climbing. When 10% fused corundum was added, the sample showed excellent comprehensive properties, with a shrinkage of 1.02%, a porosity of 20.91%, a bulk density of 1.7083 g·cm3, a bending strength of 14.83MPa and 20.96 MPa at room temperature and high temperature, and a high temperature deflection of 0.39 mm.