Foam concrete grouting system and method for karst area

The invention discloses a foam concrete grouting system and method for a karst area, and belongs to the technical field of karst area construction, and the system comprises a drilling unit which is used for drilling a hole in a to-be-grouted area of the karst area to form a grouting hole; the foam concrete preparing and conveying unit is used for preparing foam concrete and conveying grouting slurry; the grouting unit comprises a sleeve assembly, an isolation assembly and a grouting assembly, the sleeve assembly comprises an outer sleeve and a drainage pipe, the outer sleeve is inserted into the grouting hole, and the outer sleeve is provided with a sieve hole area corresponding to a to-be-grouted area in the grouting hole; the isolation assembly comprises a first isolation piece and a second isolation piece which are arranged at the two ends of the sieve hole area of the outer sleeve correspondingly. The grouting assembly comprises at least one grouting pipe. The device is simple in structure, reasonable in