Fracturing string and segmented re-fracturing operation method of horizontal well

The invention provides a fracturing string and a segmented re-fracturing operation method of a horizontal well. The fracturing string comprises an oil pipe, a hanger, multiple packers and a releasingtool, wherein the oil pipe is divided into multiple pipe segments, is used as a base pipe so as to be in threaded connection with various tools of the string, provides a fracturing liquid feed channel, and penetrates through a sleeve pipe of the horizontal well; the hanger is arranged on the oil pipe, so that the whole fracturing string is fixed into the sleeve pipe; the hanger and the sleeve piperealize building and relieving of fixed constraint through slips; the multiple packers are connected onto the oil pipe through screw threads; the oil pipe comprises multiple pipe segments connected in order; the pipe section provided with the hanger is connected with the adjacent pipe section through the releasing tool; and the releasing tool is located above the hanger. The fracturing string andthe segmented re-fracturin