This study explores the development of high-speed swept source with a wide imaging range and instantaneous line width. For the swept source in the 1.3 μm band, the sweep rate is 193.25 kHz through the sampling buffer structure, the maximum tuning range is 142.34 nm. Meanwhile, the numerical model of the SS-OCT system is established and the signal in the OCT imaging process is numerically simulated. The influence of the dispersion mismatch point diffusion function on the imaging system is studied. Simulation results provide valuable guidance for the selection of optical components in the SS-OCT systems.