Dual-beam ion irradiation with Si- or si and He ions was used to simulate expected fusion conditions. Indentation techniques were used to determine the changes in hardness, modulus and indentation fracture toughness in dual-ion irradiated β-SiC at temperatures range from 673 to 1673 K. Ion irradiation clearly enhanced radiation induced hardening. Also, appreciable hardening by simultaneous helium injection revealed after dual-ion irradiation. The elastic modulus of the ion irradiated β-SiC exhibited a slight decrease at low temperature irradiation, and a recovery at high temperature irradiated β-SiC. The indentation fracture toughness increased after both single- and dual-ion irradiation for dose up to 1-3 dpa, then decreased for higher temperature and longer irradiation.