As the structure of chain-type tool magazine is compact,and the positioning precision of chain-type tool magazine is high,the chain-type tool magazines are extensively adopted by largescale machine centers.The key feature of the chain-type tool magazine is to put toolcases in a closedloop chain to reserve tools with an robotarm to change tools for the machine center.In order to change the tool precisely,the robotarm is required to finish series of complicated and fluent movements without any failures occurring,such as dropping the tool.Based on the specific requirements and the layout of VMC 630 vertical machine center,a chain-type tool magazine was designed.The reliability of measurements of tool positioning and tool gripping was analyzed.The key technology was summarized by actual manufacturing of chain-type tool magazine design.