The invention discloses a preparation method of mild reaction type aldehyde ketone resin. The mild reaction type aldehyde ketone resin is prepared by adding a quantitative superbase catalyst into mixed liquid of aldehyde and ketone compounds under the condition of stirring at normal temperature, wherein the reaction process is mild and stable, so the defect that the traditional furfuraldehyde acetone system is easy to implode is overcome. The invention also discloses an application of the mild reaction type aldehyde ketone resin to preparation of an aldehyde ketone resin modified epoxy grouting material. The prepared grouting material can completely exert the flexibility of the aldehyde ketone resin, solves the problem that epoxy resin has high brittleness, can further improve excellent mechanical properties, adhesive property, ageing resistance and corrosion resistance of the epoxy resin, and also has the characteristics of low toxicity, environmental friendliness and the like. In addition, according to the preparation method, the aldehyde ketone resin is prepared in advance and has higher viscosity and thixotropism when being used together with fillers, so the construction process is simple and the aldehyde ketone resin can be applied to concrete surface corrosion of basic facilities such as bridges and ports, restoration of cultural relic, water and seepage prevention, reinforcement and strengthening of buildings and the like.