We develop a quantum vacuum measurement device based on a Fabry-Perot laser resonant cavity and use the beat frequency and the Pound Drever Hall (PDH) laser frequency-locking technology to accurately measure the change of resonant frequency in the cavity before and after inflation. The refractive index of dry Ar at the temperature of 299.1485 K and the vacuum degree of 10 ²-10 ⁵ Pa is measured. With the measurement result by the capacitance diaphragm vacuum meter, we get the relation coefficient of 2.50835×10 ^-9 between refractive index and vacuum degree. In addition, we compare and analyze the difference between the retrieved and measured vacuum degrees, and finally, we evaluate the laser frequency uncertainty as well as the refractive index and vacuum measurement uncertainty. The results show that the laser frequency uncertainty is 5×10 ^-12, the refractive index measurement uncertainty is 1.64×10 ^-8, and the vacuum measurement uncertainty is 2.5×10 ^-4. The developed quantum vacuum measurement device based on the Fabry-Perot laser resonator has been used to realize the quantum vacuum measurement, which provides some reference for the research of quantum vacuum measurement technologies in China.