The invention relates to a 
solid desulfurizer and a production method thereof, in particular to a composite 
calcium-based 
solid desulfurizer which is prepared from 
industrial waste residues and the production method thereof. The desulfurizer is prepared by the following steps of: directly mixing 
carbide slag slurry, dicyandiamide 
slag serving as a modifier, a chemical 
drying agent and 
magnesium slag powder which serves as another modifier; stirring and mixing; performing 
wet milling to prepare 
slurry; performing dry milling to prepare 
powder; and sieving. The prepared composite 
calcium-based 
solid desulfurizer is mainly compounded by 
calcium hydroxide or 
calcium hydroxide and 
calcium carbonate, wherein the desulfurizer contains an active 
magnesium oxide component, integrates the characteristics of a single calcium base or a 
magnesium-based desulfurizer and has composite effects. Moreover, the desulfurizer has the characteristics of saving a large amount of energy, protecting environment and reducing the cost of a 
flue gas desulfurizer, along with cheap and wide 
raw material resource, large amount of doped magnesium slag, 
carbide slag and dicyandiamide slag, no heat source, high 
dehydration speed, stable 
physical performance and the like; in addition, the desulfurizer has the advantages of small equipment investment, low operation cost, capability of eliminating the damage of limestone exploitation to the environment and the like.