The　security　of　BPEL　(Business　Process　Execution　Language)　based　manufacturing　service　workflow　management　system　is　researched　in　this　paper,　in　order　to　achieve　the　efficient　and　secure　integration　and　sharing　of　dispersed　and　heterogeneous　design/manufacturing　resources,　and　to　realize　the　reuse　of　the　complex　distributed　Design/Manufacturing　process　models.　By　integrating　the　secure　BPEL　engine,　proxy　credential　server　and　authentication　trust　level,　the　security　framework　of　the　BPEL　based　manufacturing　service　workflow　management　system　is　built　up,　and　the　security　mechanism　of　integrating　BPEL　and　WSRF　(Web　Service　Resource　Framework)　is　analyzed.　In　addition,　the　system　implementation　technologies　are　analyzed　and　a　distributed　injection　mould　Design/Manufacturing　application　scenario　is　described.　The　research　results　provide　the　basis　for　developing　a　secure　BPEL　based　distributed　Design/Manufacturing　prototype　system.