Abstract: In order to solve the distillation separation sequence synthesis problem effectively, super or neighborhood structure must be researched, and it is the foundation of realizing optimization algorithm. Because there is analogous structure between the distillation separation sequence and the binary tree, distillation separation sequence can be described as binary tree data structure, and then adopt the method of graph theory to study it. Distillation separation sequence synthesis problem has been further researched with combinatorial mathematics theory, and the computing complexity of sequence decomposition problem has been concisely analyzed; random search for distillation separation sequence has been implemented; what's more, through the change mechanism of neighboring split position in binary tree, the equivalent rules of neighboring change based on post order traversal has been abstracted, consequently, a kind of high effective evolutional neighborhood (super) structure has been constructed.