The feasibility of offshore tandem lifting test for the semi-submersible lifting and disassembling unit has been discussed based on the procedure of the offshore tandem lifting with a 2 000 t crane, combining with the performance properties of the crane and the actual experiment environment. The operation of each segment in the procedure of the tandem lifting can be safe and reliable according to the characteristics of the unit. It can provide a theoretical basis for the later offshore tandem lifting test of the semi-submersible lifting and disassembling unit. The analysis results show that the tandem lifting procedures that meet the requirements of feasibility and safety can be tested at sea.