Construction method of clay core wall of earth rock cofferdam

The invention discloses a construction method of a clay core wall of an earth rock cofferdam, which comprises the following steps: arranging a plurality of pile positions on the clay core wall, drilling at each pile position to form a blind hole, recording the depth range of a drill bit when the bit pressure is abnormal in the drilling process, and marking the depth range as an abnormal section; a sleeve is inserted into the blind hole; the grouting pipe extends into the casing pipe and sinks to a preset position, grout is injected through the grouting pipe, the casing pipe is broken through spraying, the grouting pipe rotatably ascends in the grout spraying process, the difference value between the preset sprayed face elevation and the actual sprayed face elevation is calculated every first preset time in the abnormal section, if the difference value exceeds the preset difference value, grout spraying is paused, and if the difference value does not exceed the preset difference value, grout spraying is stoppe