The theory and process of dynamic stability analysis are studied based on hard seabed. The static stability analysis method is used to preliminarily screen the stability of the subsea pipeline and cable, and the dynamic stability analysis is used for the pipeline and cable which can not maintain absolute stability. The finite element method is used for the dynamic stability analysis of the umbilical cable, and the analysis results are compared. The analysis results show that the displacement and force condition can be estimated exactly by dynamic stability method, which is suitable for hard seabed and other specific soil. In the meantime the commonly used stabilization measures of the subsea pipeline and cable in engineering are introduced according to the characteristics of hard seabed.