The hydration kinetics of carbonized spinel carbon bricks with different proportions of Mg / A1 additive has been studied in water steam of super thermostatic bath between 25°C and 85°C.The kinetic equations for hydration of the brick have been derived according to the experimental data and the theory of kinetics. Methods of various protections against hydration have been discussed. It shows that chemical reaction control occurs in the carbonized spinel carbon brick with Al and Mg at 44.3°C-84°C. The cracking time reduces from 40h to 4h with the rising of temperature verifies from 44°C to 84°C, the hydration is controlled by diffusion between 24.7°C and 33°C. And cracking does not appear after 50-day-and-night hydration at 24.7°C.