▎ 摘　　要

NOVELTY - Rare earth-based thermal insulation composite fiber is prepared mixing the mixed slice (1) and (2) by melt spinning. The mixed slice (1) comprises 1-30 wt.% rare earth thermal storage functional powder and a fiber-forming polymer, the mixed slice (2) comprises the fiber forming polymer or a mixture of 0-10 wt.% rare earth thermal storage functional powder and the fiber-forming polymer. The rare earth thermal storage functional powder comprises powder (A), powder (B) and powder (C) in the mass ratio of (1-3):(1-3):(4-8). Powder (A) is at least one of lanthanum oxide, cerium lanthanum oxide and cerium lanthanum phosphate, the powder (B) is at least one of praseodymium hexaboride, lanthanum hexaboride, cerium hexaboride, rubidium hexaboride, europium hexaboride, yttrium hexaboride, lanthanum europium hexaboride, lanthanum cerium hexaboride and a carbon black graphene mixture, and the powder (C) comprises tin antimony oxide and/or cesium tungsten bronze. USE - Rare earth-based thermal insulation composite fiber for forming warm-keeping fiber fabric for clothing or home textile (all claimed). ADVANTAGE - The rare earth-based thermal composite fiber has excellent heat storage and heat preservation performance, and the rare earth heat storage and warm-keeping improves the human skin temperature by 1-5°C. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) the preparation of rare earth-based thermal insulation composite fiber; (2) preparation of a rare earth thermal storage functional fabric from the rare earth-based thermal composite fiber.