• A direct mechanical measurement-based mooring tension monitoring method was developed and successfully deployed on the 'Yongle' platform, capturing one year of in-situ data.
• Under wave heights up to 1.24 m, the mooring tension reached 16.5 tons, demonstrating the system's capability to record extreme loads.
• Frequency domain analysis identified three distinct spectral components: wave-induced force, slow drift force, and elastic restoring force, with the restoring force frequency approximately half that of the wave signal.
• For the dual-module floating platform with hinge connections, wave-induced force was the dominant component under certain conditions, while the restoring force was the smallest.