Abstract：Different excavations and support sequences have a great effect on the stability of slope. Based on centrifuge model tests and numerical calculation，the deformation failure and stress field due to different excavation and support sequences，are analyzed. The results show that the prompt support after being cut can reduce the deformation magnitude of slope and can improve the stability of slope(the centrifuge model tests of soil slope with two cut stages show that prompt support after being cut，the failure acceleration is 14.15% higher than once support after the whole being cut；the up stage with prompt support，but down part without prompt support is 8.49% higher than that of once support after the whole being cut). The mechanism of prompt support with high stability is that the concentration degree and connection of the maximum shear stress are weak，but the stress loose degrees are low. At last，those very high slopes cut with multilevel stages should be supported temporarily to uphold stages first，and then to hold permanent support after the whole slope being cut. Thus，it meets sufficiently the“New Austrian”principle and satisfy the requirements of slope stability with a lower cost. The results have practical significance for engineering practice.
