Dewatering construction method suitable for high-pressure-bearing water-rich karst stratum deep foundation pit

The invention provides a dewatering construction method suitable for a high-pressure-bearing water-rich karst stratum deep foundation pit. The dewatering construction method comprises the following steps that 1) dewatering well construction is conducted; 2) blind ditch position planning is conducted; 3) blind ditch excavation is conducted, specifically, according to the planned blind ditch position, a blind ditch is excavated in the bottom face of the foundation pit, the depth of a groove of the blind ditch is controlled to be 15-25cm, the width of the groove of the blind ditch is controlled to be 25-35cm, and the gradient of the groove of the blind ditch is controlled to be 0.1, so that gushing water flows to a dewatering well from karst fracture gushing water points in the deep foundation pit; 4) filter pipe mounting is conducted; 5) gushing water point drainage is conducted; 6) inverted filter layer backfilling is conducted; and 7) drainage is conducted. According to the dewatering construction method suit