For studying the performance of spiral wound heat exchangers (SWHEs) applied in the LNG-FPSO (LNG Floating Production Storage and Offloading unit) dual mixed refrigerant (DMR) liquefaction process, an experimental device and a numerical simulation model of DMR liquefaction process are established. Based on the experimental results and the REFPROP software, the effects of sloshing on the performance of SWHE are selected as the disturbances to test the responses of the DMR liquefaction process. The results show that the sloshing-induced reduction of SWHE heat transfer performance is within 50% for all sloshing cases. The decrease of specific power consumption of DMR liquefaction process is within 13%, when the SWHE is under sloshing angles from 3° to 9° and sloshing periods from 6 s to 30 s.