With the continuous improvement and development of optical communication technology, equipment manufacturers are demanding increasingly stringent accuracy requirements for the performance indicators of high-speed optical communication devices. Scattering parameters (S parameters) can accurately characterize the transmission characteristics of optical communication devices. In traditional separate and integrated measurement instruments, random errors generated during individual measurement exhibit change irregularly over time. They cannot be eliminated through calibration, but the stochastic impact on measurement results can be reduced through averaging. In view of this, an automatic measurement system for high-speed broadband optical network parameters is proposed, which can perform multiple continuous measurements of optical communication devices after one connection and calibration under the high-speed broadband conditions, thereby avoiding the drift errors caused by repeated disconnection, connection and calibration of devices between different measurements and reducing the impact of random errors within the same connection on the measurement results. Theoretical analysis and experimental results show that this design has better measurement repeatability, higher accuracy and better reliability.