The motion response of cylinder FPSO under wave with different approaches to model current in experiment are investigated. In this study, the motion responses are analyzed in frequency domain and time domain. The current is modeled by direct applying the equivalent current force and current generated in basin. The result shows that the change in full loaded and ballast loading condition have little effect on the motion of FPSO; the direct superimposed of equivalent current force will barely influence the form of cumulative distribution of 6 degree-of-freedom (DOF) responses, but with slightly changes in the equilibrium position of 6 DOF responses. Considering wave-current interaction, the surge amplitude increases significantly even if the reduced velocity is less than the lock-in region. Because real environments can be harsher than the experimental one, wave–current interaction should be taken into consideration when designing FPSOs. With the coupling of current, the transverse motion tends to be distributed in a wider range with larger amplitude. The spectral peak frequency in low-frequency (LF) move to lower frequency for sway and pitch responses under wave-current interaction. And the mean amplitude of LF and wave-frequency (WF) of 6 DOF responses are also significantly amplified