The invention discloses a test platform for the marine adaptability of a floating natural gas liquefaction system, which comprises a medium circulation module, a Freon pre-cooling module, a liquid nitrogen cooling module, a test unit, a shaking unit and a high-speed camera system; the output end of the medium circulation module is connected with the Freon pre-cooling module, the liquid nitrogen cooling module and the test unit in sequence; the Freon pre-cooling module is used for circulation of a Freon refrigerant; the liquid nitrogen cooling module is used for circulation of a liquid nitrogenrefrigerant; the test unit is an experimental model of equipment to be tested; the test unit and the high-speed camera system are set on the shaking unit; and the high-speed camera system is used torecord the gas-liquid phase interface in the test unit in real time. The test platform realizes the research on the gas-liquid phase fluctuation of a two-phase flow device during the shaking process by real-time recording and monitoring the gas-liquid phase interface through the high-speed camera system; and the test unit is placed on a shaking platform to obtain the shaking boundary condition ofthe running stability of key equipment in the FLNG process by adjusting the shaking platform.