Early strength composite Portland cement

The invention discloses a method for preparing composite Portland cement by utilizing waste glass as a main raw material. The composite Portland cement is prepared from 20-50% of waste glass, 30-60% of cement clinker, 2-6% of gypsum and 5-15% of other mixed materials by mass. The novel composite Portland cement is obtained by mixing the materials uniformly and then grinding the mixture to 80mu m, wherein the weight of screen residues is 3-5%. The method is simple in process and low in cost, is especially suitable for waste glass difficult to recycle, effectively protects the environment, promotes recycling of solid wastes, and has obvious economic, environmental and social benefits.