Abstract: With the rapid development of wind power industry, large amounts of end-of-life wind turbine blade are generated, and their disposal has become a global environmental challenge. Pyrolysis is an important technology to recover glass fibers from end-of-life wind turbine blade, while the mechanical properties of recovered glass fibers depend heavily on the recovering conditions. Therefore, the pyrolysis characteristics of wind turbine blade and the evolution of recovered glass fibers’ mechanical properties were investigated. The results revealed that as the pyrolysis temperature increased, the decomposition of epoxy resin was promoted. When the pyrolysis temperature reached 500°C, the decomposition of epoxy resin was almost complete, while further elevating the pyrolysis temperature facilitated the secondary cracking of oligomers. Besides, high temperatures could assist in the removal of unsaturated structures within the pyrolysis char, reducing its yield and the amorphous degree, thereby shortening the oxidation duration. In addition, compared with the pyrolysis stage, the oxidation removal of pyrolysis char had more significant effects on the mechanical properties of recovered glass fibers. The conclusions can provide theoretical support for the pyrolysis disposal of end-of-life wind turbine blade, supporting the recovery of high-quality glass fibers.