The mix ratio of sand-mudstone mixed filler is a key factor affecting the bearing capacity and stability of the wharf foundation.To study the creep mechanical properties of sand shale mixed fill soil under different mix proportions，shear creep tests are carried out.The results show that under the same mix ratio，the instantaneous and creep strain and the initial and steady creep rates increase gradually with the increase of the loading level of shear stress.When at the same loading level，the initial，steady-state，and ultimate accelerated creep rates，as well as instantaneous and creep strains，all show a decreasing trend with the increase of the proportion of mudstone particles in the mix ratio.The long-term srength reduction of mixed filler is relatively large，ranging from 50.53% to 66.95%，and the long-term strength decreases with the increase of the proportion of mudstone particles in the mix ratio.The research results can provide some references for the long-term stability evaluation of the mixed sand-mudstone filling foundation of the wharf.