Considering the defects of design and practical development of the relay coordination software， the rational unified process（RUP）“4+1” view method is proposed to make a macroscopic description and modeling. By proceeding from the system demand and function analysis， a comprehensive planning process is made from logical function analysis to physical deployment through four view modeling with the design patterns applied to achieve four function modules in logical view， namely， equipment graphic modeling， network topology analysis， setting calculation principle and database access， which provide greater logical reusability， expansibility and flexibility of the system.