Cold rolling coil carriage is the key process equipment responsible for the transportation of steel coil.The design of its hydraulic system not only needs to meet the process parameters such as large lift force,multi-stage lifting speed and height of steel coil,but also requires stable operation and high safety,otherwise it will lead to frequent failures and even major safety accidents.Through theoretical calculation,schematic design and component selection,the hydraulic system design of coil carriage is completed in this paper,and the design is checked and optimized by AMEsim simulation software.The results show that the design can meet the production process requirements and site safety requirements.