Abstract: The key FLNG liquefaction technologies, including the selection of liquefaction process and the adaptability of process and key device under sloshing conditions, have huge impacts on the investment, operation stability and safety of equipments. In this paper, the liquefaction processes were compared according to the offshore process design criteria. Then, two liquefaction experiment devices were built, and they are the nitrogen expansion device and the mixed refrigerant device. And finally, sloshing experiments were carried out to verify the adaptability of the technology and device in offshore conditions. It is concluded that under sloshing conditions, propane pre-cooling dual nitrogen expansion process and double mixed refrigerant process are both high in processing and liquefaction capacities. The former is suitable for the rough sea conditions with small-scale FLNG production, while the latter is applicable to the smooth sea conditions with large-scale FLNG production. The instability of falling film flow along the shell side is the main factor which results in the lower adaptability of spiral tube heat exchanger than that of plate-fin heat exchanger. Tilting and rolling deteriorate significantly the liquid distribution uniformity and mass transfer performance of the packed column. In addition, the resonance period affects directly the filling degree of the membrane-type tank, the rolling can improve the balance degree in the process of gas-liquid separation, and the sloshing has no effect on the operating performance of expanders.