The invention discloses a double-carbon cloth flexible lithium-sulfur battery and a preparation method thereof, and belongs to the technical field of preparation of lithium-sulfur batteries. The lithium-sulfur battery comprises a flexible positive electrode, a flexible negative electrode, a PP diaphragm, an electrolyte and an aluminum-plastic film; in the preparation process, both the positive electrode and the negative electrode use commercial flexible carbon cloth as carriers; through use of the carbon cloth as the positive electrode carrier, the problem of the conductivity of elemental sulfur can be effectively solved and the problem of shedding of an active substance from an electrode after bending of the electrode prepared according to the conventional coating method can be avoided; through use of the carbon cloth as the negative electrode carrier, on one hand, the flexibility of the metal lithium negative electrode can be effectively improved, and on the other hand, the carbon cloth as a three-dimensional conductive skeleton can effectively disperse the current, so that the metal lithium can be uniformly dissolved and deposited in the charge and discharge process, growth of dendrites is inhibited, and thus the service life of the battery is prolonged. A CC@Co/CNTs material is prepared for the first time, and has a higher specific surface area and higher electrical conductivity than those of a carbon cloth raw material.