A centrifuge model test was conducted on the deformation and failure of a cohesive soil steep slope under the water-level rising conditions. The failure mechanism was analyzed based on integrated analysis scheme of deformation and failure processes using measured displacement of the slope. The test results showed that the water-level rising resulted in a progressive slippage failure of the slope which started at the toe and gradually developed upwards to form an integral slip surface with the tensile cracks on the top. The water-level rising process induced significant deformation and concentrated within a limited zone. The development of deformation localization resulted in the local failure of the slope and the coupling development of both was essential to the full slip surface of the steep slope. Significant deformation occurred after the full slip surface appeared and the deformation characteristics of each point were related to its location.