The utility model discloses a grouting structure applicable to a karst region. The grouting structure applicable to the karst region is used for processing a geological flaw segment (3) in the karst region, the geological flaw segment (3) is located below base rock (1), the structure is provided with at least three drilling holes (2) which vertically go deep into the base rock (1), and the bottoms of the drilling holes (2) extend to the geological flaw segment (3); at least two of the three drilling holes (2) are air and water inlets (4), and one drilling hole (2) is a washing outlet (5). The high-pressure combined washing grouting method is an economical and efficient grouting processing technology used for karst caves, corrosion fissures and other geological flaw sections, and the structure has the advantages that the method is simple (special construction equipment and operators are not needed), the washing effect is remarkable, construction efficiency can be substantially improved and grouting quality is guaranteed.