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 demonstrates 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...