Preparation method of core-shell structure microgel concrete internal curing agent

The invention discloses a preparation method of a core-shell structure microgel concrete internal curing agent. The preparation method comprises the following steps: step 1, preparing a first solution and a second solution; 2, mixing the first solution and the second solution under the protection of nitrogen; step 3, adding an accelerant into the mixed solution, stirring at a constant temperature, standing, and washing and drying a precipitate after standing to obtain white powder; 4, adding the white powder into ammonia water, and fully swelling to obtain a swelled substance; 5, adding the swelled substance into the first solution, and uniformly dispersing to obtain a dispersion liquid; step 6, mixing n-heptane and an oxide precursor, adding the mixture into the dispersion liquid, violently stirring, and standing; and 7, washing and drying the precipitate to obtain the concrete internal curing agent. The concrete internal curing agent prepared by the method disclosed by the invention is in a regular microsph