In recent years, fluorescent organic–inorganic hybrid nanomaterials have received much interest as potential fluorescent sensor materials. In this study, fluorescent organic–inorganic hybrid nanomaterials (POSS@ANT) were created using polyhedral oligomeric silsesquioxane as the precursor and 9,10‐bromoanthracene as the monomer. The morphology and composition of POSS@ANT, as well as its pore characteristics and fluorescence properties were studied. POSS@ANT displayed steady fluorescence emission at an excitation wavelength of 374 nm. Next, a β‐carotene fluorescence sensor was developed using the capacity of β‐carotene to quench the fluorescence of POSS@ANT. The quenching process is linked to acceptor electron transfer and energy transfer, and the sensor has a high selectivity for β‐carotene. This β‐carotene fluorescence analysis method that we established has a linear range of 0.2–4.3 mg/L and a detection limit of 0.081 mg/L. Finally, it was used to quantify β‐carotene in health products, the recovery rate was 91.1–109.9%, the relative standard deviation (RSD) was 2.2–4.3%, and the results were comparable with the results of high‐performance liquid chromatography. The approach is reliable and can be used to determine β‐carotene in health products.