Abstract: The main scientific goals achieved by the Queqiao-2 relay satellite and the payload configuration are briefly introduced. Based on the characteristics of the payload technical solution and the resource conditions of the relay satellite platform, a scientific overall technical solution design for the payload was carried out, including system integration structure design, power supply and distribution safety design, scientific data processing, software system and working mode design, etc. In view of the characteristics of scientific payloads such as multiple in-orbit working modes, long service life and lightweight requirements, a scientific payload manager was designed to tightly couple and integrate subsystems, simplifying the interface with the relay satellite platform. Through the design of power supply and distribution safety and software system maintenance, the fault handling capability during in-orbit operation is enhanced to meet the requirements of an in-orbit mission lasting up to eight years.