Abstract: The rim-seal performance of the turbine has an important role in the design of the secondary air system and rim-seal structure of gas turbine, which is influenced by three-dimensional unsteady flow in the disc cavity. Studies of the sealing characteristics and flow mechanism were carried out by researchers to understand the cavity flow from quantitative and qualitative aspects. Related work has received more and more attention as the turbine inlet temperature rises and detailed design is needed. Based on extensive literature research, the article introduced rotation induced, external induced and combined sealing characteristics, the steady flow structure and unsteady flow inside the axial and radial turbine disc cavity. Further research work of rim-seal performance and flow mechanism in turbine cavity was addressed.