In order to optimize the parameter settings of the time-gated digital optical frequency domain reflectometer (TGD-OFDR) system, an experimental system was built based on the optical pulse compression reflectometry. Theoretical analysis and experimental verification were carried out, and simulation and experimental data were obtained. Both of the results show that the system signal-to-noise ratio (SNR) is only related to the chirp rate. When the pulse power of the probe light and the signal power of the local oscillator light have been set, the chirp rate increases with the SNR decreasing. And the phase noise decreases firstly and then increases with the increase of the pulse width with the minimum value of about 2.5μs when the sweep range keeps 80MHz. Hence, the optimal phase noise (minimum value) can be obtained by adjusting the pulse width with the maximum sweep frequency range of the system remains unchanged. The results have certain reference significance to the parameter optimization of the TGD-OFDR system design.