The invention provides full-spectrum high-brightness high-stability fluorescent dye. The dye is prepared by mixing one or more selected from 4-acylamino-substituted naphthalimide dye, bialkoxy-substituted naphthalimide fluorescent dye, diamino-substituted naphthalimide fluorescent dye, 9,10-diamino-substituted perylene bisimide dye, six-membered rhodamine dye, five-membered rhodamine dye, and Si-rhodamine dye according to any ratio. Compared with existing commercial dye, the fluorescent dye provided by the invention is higher in light stability, narrower in half-peak width (25 nm) and insensitive to various external environments such as pH, polarity, temperature and the like. Through introduction of Click groups, protein labels, drug molecules and other active groups, the obtained functionalized fluorescent molecules have very high biocompatibility, and can be used for rapid and specific staining of living cells and living bodies. In addition, due to the improvement of light stabilityand fluorescence brightness, the dye realizes super-resolution fluorescence imaging in various modes such as Storm, STED and SIM.