The invention discloses a concrete moisture evaporation inhibitor and a preparation method and application thereof. The concrete moisture evaporation inhibitor is prepared by taking unsaturated acid, unsaturated amide and unsaturated ester as main raw materials and is polymerized by adopting a water solution free radical method with mass ratio of 1:(1-2.5):(0.0-0.1). A moisture evaporation inhibitor solution is introduced into the concrete by an external spraying or internal doping mode, evaporation of surface moisture at the plastic state of the concrete can be obviously inhibited, plastic cracking of the concrete is greatly reduced, and the concrete moisture evaporation inhibitor and the preparation method and application thereof have the advantages of being simple in process, green and environment friendly, convenient in use and good in anti-cracking effect.