A novel composite fluorescent probe (SCDs) was synthesized by forming a covalent bond be tween mes-oporous SBA-15 functionalized with 3-glycidyloxypropyltrimethoxysilane (SBA-15/560) and mul-ti-hydroxyl carbon dots (CDs). The composite probe was characterized with TEM, FT-IR and XPS analysis, the results showed that the multi-hydroxyl CDs were successfully assembled into the SBA-15/560, indi-cating that the obtained SCDs nanocomposite probe not only maintained excellent fluorescence proper-ties of multi-hydroxyl CDs but also highly ordered structure of mesopores. Subsequently, the composite fluorescent probe was used for 2,4,6-trinitrophenol (TNP) detection. It was found that the composite probe had a selective and sensitive response towards TNP. The results of the TNP assay show that the composite fluorescent probe exhibits two wide linear regions in the range of 1~8 and 10~70 μmol/Lwith a low limit detection of 0.17 μmol/L. The results confirmed that the composite probe could be used as a promising sensor for TNP detection.