Abstract: The drag coefficients of spherical and non-spherical particles are calculated based on the immersed smooth finite element model (IS–FEM). A particle drag image measurement experiment is designed to verify the numerical simulation result. The motion of particle is solved by smooth finite element method with continuum theory. The fluid governing equation is solved by semi-implicit characteristic-based split method. Data exchange between particle and fluid phase is carried out in non-fit mesh. The results show that the velocity field around spherical particles are symmetrically distributed, and the long axis of the non-spherical particles is perpendicular to the gravity direction when the particles are in a stable settlement. The calculated drag coefficients of spherical particles are consistent with the Stokes theory under different Reynolds numbers, and the drag coefficient of non-spherical particles is higher than that of equivalent spherical particles. The predicted value of IS-FEM is in good agreement with the experimental measurement.