By Cambrian-Ordovician sedimentary and seismic characteristics analysis in Ba-Mai area of Tarim Basin, the results show that those area experienced evolution of the ramp-type carbonate platform slope to the edge of platform-type. The evolution of ramp-type platform in Early-Middle Cambrian, due to frequent movements of sea level changes, platform margin has experienced three migration. Late Cambrian extensional area in the formation of passive continental margin environment, sea level began to rise, development platform edge slope type, Relative sea-level rise rate is less than the supply rate of sediment, Platform migration towards the basin edge. Early Ordovician sea-level rise rate is accelerated, sea level rise rate is greater than the deposition rate, platform type stacking patterns to make up the direction of migration to the platform.
