The invention provides cement-based multi-polymer dry mixed powder, a preparation method and a construction process thereof. The dry mixed powder comprises the following components in percentage by weight: 25 to 30 percent of No.42.5 cement, 20 to 25 percent of No.32.5 cement, 25 to 35 percent of triple superphosphate powder, 5 to 10 percent of gypsum powder, 1 to 3 percent of dispersible latex powder, 3 to 3.5 percent of starch ether, 1 to 3 percent of bentonite thixotropic lubricant, 1.5 to 2.0 percent of organic silicon, 0.15 to 0.20 percent of water repellent agent, 0.20 to 0.30 percent of methylcellulose and 0.30 to 0.60 percent of cellulose fiber. The preparation method for the dry mixed powder comprises the following steps: mixing the No.42.5 cement, No.32.5 cement, triple superphosphate powder, gypsum powder, dispersible latex powder, starch ether, bentonite thixotropic lubricant and organic silicon evenly according to the proportion, then adding a mixture of the water repellent agent, the methylcellulose and the cellulose fiber into the mixed substances, and stirring the mixture evenly to form the cement-based multi-polymer dry mixed powder. The construction process for the dry mixed powder comprises the following steps: mixing and stirring the dry mixed powder and sand evenly, adding proper amount of water into the mixture, and stirring the mixture to form a colloid substance.