The application of blue phase liquid crystals (BPLCs) in optical control devices has been widely studied due to their fast response characteristics. However, the fabrication of free-standing BPLC fiber with emerging functionalities is challenging. Here, we demonstrate a free-standing fiber based on BPLC with excellent stability, flexibility, and multifunction. The multi-mode fiber (MMF) end face is etched by the etching agent of buffered oxide etch (BOE), which can be fixedly connected with the free-standing BPLC fiber after polymerization in order to overcome the problems of optical signals transmission and reception. Three types of free-standing BPLC fiber-based devices, including Volatile Organic Compound (VOC) vapor sensors, vector position sensors, and color fibers, are fabricated and investigated, to the best of our knowledge, for the first time. The free-standing BPLC fiber as a multifunctional material will provide broad application prospects in VOC sensors without power supply, smart fabrics, flexible displays, decorations fields with no dyes, as well as vector displacement sensors for robotic arm positioning.