A Brillouin frequency shift parameter calibration method based on optical carrier suppression modulation technology is proposed to meet the metrological calibration requirements for frequency shift of Brillouin optical time domain reflectometer (BOTDR) in distributed fiber sensors. Fiber Brillouin scattering signals were simulated using the frequency doubling signal generated by optical carrier suppression modulation technology, and a mathematical model and value traceability diagram between the Brillouin frequency shift reference value and the output signal frequency of the signal generator were provided, to achieve the value traceability of Brillouin frequency shift to the atomic time standard reference device. By adjusting the frequency of the output signal of the signal generator, the Brillouin frequency shift indication error at different frequency points within the frequency shift range can be obtained. Experiments were conducted to obtain calibration results for different frequency shift points within the range of 10.6 to 11.8 GHz, and an uncertainty analysis was performed. When the measured Brillouin frequency shift value is 10 998.38 MHz, the expanded uncertainty is 0.07 MHz (k = 2). This calibration method can meet the metrological traceability requirements for BOTDR frequency shift in the field of fiber optic sensing applications, providing strong support for promoting the performance improvement and widespread application of BOTDR.