Abstract: With the development of aerospace technology and computer technology, software has become an important component of spacecraft, effectively enhancing the functionality, performance and flexiblility of spacecraft. When designing the software system, it faces the characteristics of multiple functions, numerous constraints and systematicness. The systems engineering methods provides important theoretical support and design methods for the software system design.This paper proposes the idea of using systems engineering methods to carry out spacecraft software system design, explores the relationship between the systems engineering method and the software system design, establishes a three-dimensional structure for the software system design, and presents practical application cases of systems engineering methods in the software system design of telecommunication satellite.