The ABAQUS static creep calculation module was adopted to simulate the variation of strain with vi- bration frequency. The finite element software was combined with the empirical formula of undrained cumulative deformation, calculating the long-term settlement of the shield tunnel under the cyclic loading of subway trains in Foshan area, which improved the calculation accuracy and efficiency. The relevant parameters in the cumula- tive settlement empirical formula were determined by the dynamic triaxial test results of the silt soft soil in Fos- han. Besides, this method was adopted to predict the cumulative deformation of an interval tunnel in Foshan Rail Transit Line 3 under the long-term load of subway trains. The research results show that as the depth increases, the cumulative plastic deformation is smaller. The accumulated plastic deformation caused by the operation of Foshan Rail Transit Line 3 below the muddy soil part reaches 36 mm over the past 20 years, and the accumulat- ed deformation for one year is about 20 mm.