Abstract: With rapid development of radar technology, radar software upgrade has become increasingly frequent. Maintainability becomes an important standard to measure software quality. Based on the seven quality characteristics of software maintainability, this paper systematically expounds the technical design measures of radar software maintainability according to every stage of software lifecycle and proposes the integrated application of the open software architecture, software middleware technology, component-based soft development and management, software design parameterization, real-time reconstruction technology based on condition monitoring and diagnosis, and interface usability design to improve radar software maintainability.