The copper oxide bed regenerable adsorber process can efficiently remove sulfur dioxide (SO2) and sulfur trioxide (SO3) and reduce nitrogen oxides (NOx) from flue gas with no solid or liquid byproducts. This paper investigates the dry flue gas desulfurization activities of the CuO/γ-Al2O3 under different operation conditions finding that the dispersion degree of copper oxide can achieve a threshold value, which is 0.47mg/m2 carriers. The conclusion confirms that the sulfur capacity of desulfurizer is associated with flue gas' space velocity, reaction temperature, copper content and the structure of sorbent pellet, etc. And with the condition of the desulfurization reaction temperature 673 K, the space velocity 11 200 h-1 and the S/Cu mole ratio under 1, the sulfur removal efficiency can go upwards to 95%.