Influence of two-phase flow on the oil film characteristic of squeeze film damper(SFD) under extremely low oil supply pressure was investigated through tests. The test results showed that the oil film damping decreased with the increase of gas volume fraction when the gas volume fraction is under 0.9. As the gas volume fraction reached 0.9

the damping was 60% of the damping of pure oil. The damping decreased dramatically to negligible

as the gas volume fraction continued increasing beyond 0.9. The trend can not be predicted by the existing theoretical model. Based on the test results

the best-fitting model for the two-phase flow of SFDs was used to predict the damping coefficients of SFD

which can match the test results under both large and low oil supply pressures. The model can provide a reliable theoretical basis for the selection of SFD two-phase flow model.