Method for fracturing composite pipe column through hydraulic jetting in segmented mode

The invention discloses a method for fracturing a composite pipe column through hydraulic jetting in a segmented mode, which comprises the following steps: (1) descending a jetting and fracturing device down to the layer position to be constructed in a well through a working pipe column, (2) calibrating the position of the jetting and fracturing device, aiming the layer position to be constructed and then throwing a ball to seal and plug a first stage bottom spray gun, (3) descending a perforation liquid pump into the jetting and fracturing device through the working pipe column and forming a perforation eyelet in the stratum, (4) pumping fracturing fluid into the underground jetting and fracturing device through the working pipe column and enabling the perforation eyelet to fracture and extend to form a gap, (5) finishing one layer position fracturing, then lifting the working pipe column to move the jetting and fracturing device upward to a nest layer position to be constructed and repeating the steps (3)-(4), (6) dragging the first stage bottom spray gun to perform construction of two to three layers, then throwing a ball towards the working pipe column to open a sliding sleeve of a second stage upper-portion spray gun, and repeating the steps (3)-(5), (7) dragging the second stage upper-portion spray gun to perform construction of two to three layers, then adjusting the position of a third stage upper-portion spray gun to enable third stage upper-portion spray gun to aim the layer position to be constructed, throwing a ball towards the working pipe column to open a sliding sleeve of a third stage spray gun, and repeating the steps (3)-(5), and (8) lifting the working pipe column to fetch out the jetting and fracturing device after finishing construction of all layer positions.