Viscosity reducer for concrete with low water-binder ratio and application of viscosity reducer

The invention discloses a viscosity reducer for concrete with a low water-binder ratio and application of the viscosity reducer. The viscosity reducer is prepared by mixing a component A, a component B and a component C according to a mass ratio of (50-80): (30-20): (0-20), the component A is selected from any one or a mixture of multiple of micromolecular dihydric alcohol and micromolecular dihydric alcohol derivatives; the component B is selected from any one of glycerol and a glycerol polyoxyethylene ether derivative or a mixture of two of glycerol and a glycerol polyoxyethylene ether derivative in any proportion; and the component C is pentaerythritol polyoxyethylene ether. The structure of the micromolecular polyol and the derivative thereof in the components of the viscosity reducer is low-density non-ionic non-adsorption type molecules, has an interval effect, and can be effectively dissolved in a mesoporous solution, so that the problem that interstitial water among particles cannot be released under