The subsea cable joint environmental control chamber is a sealed, dedicated clean workspace used on vessel decks/platforms for fabricating high-voltage subsea cable intermediate joints and flexible joints in offshore wind power and cross-sea transmission projects. High-voltage cable joints (35kV/66kV/220kV) with insulation components are extremely sensitive to humidity, salt spray, dust, and condensation. Open-air fabrication in harsh offshore conditions with strong winds and heavy salt spray easily causes insulation defects, leading to breakdown failures during long-term operation. The environmental control chamber creates a sealed clean environment with constant temperature, humidity, low dust, and low salt spray throughout the entire joint fabrication process, ensuring subsea cable joint construction meets quality standards. The visual air quality detector enables real-time particulate monitoring and automatic environmental temperature and humidity adjustment.