The invention provides a method for breeding upland long-stapled cotton, which specifically comprises the following steps: carrying out the artificial cross between Xiang9520 selected as a female parent and Beiersinuo selected as a male parent according to the scientific breeding procedure; carrying out the modified backcross between the F1 generation as a male parent and Xiang9520; carrying out the multi-generation self-cross until the characters are stable; further selecting the high-grade individual-plant material from the field and carrying out the comparative test of strains to select a high-grade and high-yield strain Xiang309 with stable characters; sending the Xiang309 to space by a space ship, and further carrying out the systematic breeding process in the disease nursery after the Xiang309 is returned to the ground; and sampling and checking to obtain a over-length fiber variant individual plant, i.e., the upland long-stapled cotton named as Xiang9136. The invention has the following advantages: the technical route is advanced; the length of the bred upland long-stapled cotton reaches the length limit; and attaching importance to the high-yield selection, the single-boll weight of the Xiang9136 is 5.1g, the lint percentage thereof reaches 43.1%, the yield of unginned cotton per mu reaches 240kg, and the yield of ginned cotton per mu reaches more than 103.5kg.