Label free detection with high sensitivity, selectivity and reliability is crucial for monitoring carbon tetrachloride (CCl4) vapor, which is a kind of hazardous vapor to human health even at low concentration. In this work, we synthesized the MIL-101(Cr) through a hydrofluoric acid-free (HF-free) method and proposed a label-free high performance optical refractive index CCl4 vapor sensor based on MIL-101(Cr)/TiO2 one-dimensional photonic crystals (1DPC). The application of the MIL-101(Cr)/TiO2 1DPC in CCl4 vapor optical detection was investigated due to the excellent selectivity and ultrahigh adsorption capacities of MIL-101(Cr) for CCl4 vapor. The results illustrate that the MIL-101(Cr)/TiO2 1DPC vapor sensor shows high sensitivity of 0.11 nm/ppm with a good linear relationship in the concentrations range of 0–100 ppm CCl4 vapor and great selectivity with the value of selectivity(S) varied from 2.63 to 18 comparing CCl4 vapor with toluene (C7H8), acetone (C3H6O), n-hexane (C6H14) and dichloromethane (CH2Cl2) vapor. Meanwhile, the MIL-101(Cr)/TiO2 1DPC sensor presents a fast optical response and recovery time of 1.2 s and 12.1 s with exceptional repeatability and reliability for 100 ppm CCl4 vapor detection, which are important for practical applications.