Shield tunneling construction method for water-rich upper-soft lower-hard composite stratum

The invention discloses a shield tunneling construction method for a water-rich upper-soft lower-hard composite stratum. The shield tunneling construction method is characterized by comprising the following steps that 1) geological overview detection is conducted; 2) a cutting area is determined; 3) hole forming is conducted on the cutting area, specifically, a plurality of edge holes are drilled along the edge of the cutting area, a plurality of inner holes with the same hole depth as the edge holes are drilled in the cutting area, and the positions of the edge holes and the inner holes are controlled, so that the edge holes and the inner holes are distributed in a grid point shape; 4) drilling and connecting line cutting are conducted, specifically, ultrahigh-pressure abrasive water jet is adopted to conduct cutting along the inner holes and the edge holes, the cutting depth is controlled to be smaller than or equal to the depth of the edge holes, so that cutting lines are connected with the inner holes and