Abstract: The new method of detoxicating slag containing chromium by microwave radiation was basically studied. The experiments included those with the temperature of chromic slag and reducing agent-coal due to microwave radiation, the influence of operation conditions (such as microwave power, radiation time, compounding ratio, the quantity of coal and chromic slag) on the translation rate of Cr⁶⁺. At the same time, the orthogonal test was applied to analyze the factors. The results of the above experiments show that chromic slag and coal can absorb microwave energy, and the coal is a good carbon reductant. The strong microwave energy, long radiation time and high quantity help to increase translation ratio. After carbonaceous quantity reaches 20%, the quantity does not basically influence reaction speed. Adding quantity of coal and chromic slag has some influence upon translation ratio, but the influence is not in evidence.