Abstract: With the rapid development of new power systems with high proportion of renewable energy and high proportion of power electronic equipment, wide frequency oscillation, sub-synchronous oscillation, harmonic/inter-harmonic oscillation and other oscillation problems have become increasingly prominent. Aiming at the problem that the existing broadband measurement cannot respond to power oscillations quickly due to the limitations of its own hardware and software platforms, sampling rate and communication protocol, a high-speed synchronous sampling method and a scalable data transmission protocol with time-division multiplexing channels are proposed to ensure the synchronous acquisition and real-time transmission of high-speed data. The main function performance of the wideband phasor measuring device is tested and verified and applied in substation. The results show that the technological innovation can ensure the wideband oscillation monitoring of power system quickly and accurately.