Cristobalite was added as a high-temperature reinforcing phase to the matrix material of the SiO

2

-based ceramic core prepared by hot pressure injection.The influence of the particle size of pre-added cristobalite on the performance of SiO

2

-based ceramic cores was investigated.The enhancement mechanism of cristobalite particle size on the porosity and high temperature creep resistance of SiO

2

-based ceramic cores was analyzed.The results indicate that the apparent porosity of the SiO

2

-based ceramic core is gradually increased as the particle size of cristobalite decreases

and the room temperature bending strength and high temperature deflection are gradually decreased.When the particle size of cristobalite is 13μm

the apparent porosity of the SiO

2

-based ceramic core reaches the maximum value

and the high temperature deflection reaches the minimum value

which are 42.30% and 0.14 mm

respectively.