Composite chromium-reducing grinding aid and preparation method thereof

The invention discloses a composite chromium-reducing grinding aid and a preparation method thereof, and relates to the field of building materials, the composite chromium-reducing grinding aid comprises the following raw materials: 15-30 wt% of a chromium-reducing component, 5-10 wt% of an antioxidant component, 20-40 wt% of a grinding aid component, and the balance of water; the chromium reducing component is thiourea dioxide and/or sodium cyanoborohydride; the preparation method comprises the following steps: firstly, adding the grinding aid component and the water at normal temperature, and uniformly stirring; then adding the antioxidant component and uniformly stirring; and keeping the stirring state, adding the chromium-reducing component, and continuously stirring uniformly to obtain a finished product of the composite chromium-reducing grinding aid. The composite chromium-reducing grinding aid provided by the invention is good in chromium-reducing effect, does not rebound, has the characteristics of h