Modified desulfurization ash for cement and concrete and preparation method thereof

The invention discloses modified desulfurization ash for cement and concrete and a preparation method of the modified desulfurization ash. The modified desulfurization ash for cement and concrete is prepared from desulfurization ash and an oxidizing agent through mixing at normal temperature, wherein the oxidizing agent comprises the following components by weight percentage: 70-80% of manganese dioxide, 5-10% of acetic acid and 10-25% of desulfuration residue, the conversion rate of CaSO4.2H2O in the modified desulfurization ash is 95-98%, the mixing amount of the modified desulfurization ash in cement and concrete is 5-25% (by weight percentage). The modified desulfurization ash has early compressive strength improved remarkably when being added into the cement and the concrete, has the compressive strength hardly reduced after being solidified completely, and has little swelling stress.