Organic light-emitting diode (OLED) has important applications in the next generation of lighting, displays and related fields. Blue fluorescent dyes are essential for the fabrication of OLED. In this study, by protonating a blue fluorescent dye 6-aminoisoquinoline (6-AIQ) with benzenesulfonic acid (BSA), the fluorescence quantum yield was successfully increased from 64.71% to 85.84%. The 6-AIQ-BSA was further inserted into a barrel-shaped hydroxypropyl-β-cyclodextrin (HP-β-CD) molecule to form a supramolecular structure, which could reduce the fluorescence quenching at high concentrations. Experiments showed that white light emission could be achieved by mixing the 6-AIQ-BSA@HP-β-CD with orange light dye DAST@ HP-β-CD in a ratio of 1.7 to 1, and its CIE color coordinates were (0.332 4, 0.328 4). The prepared film has the characteristics of good white light emission, lightweight, and flexibility, which makes it has broad application potential in various light-emitting devices.