Multi-core Digital Signal Processor (DSP) is widely used in signal processing systems in aviation, aerospace and other fields. In practical engineering applications, due to the performance limitation of JTAG interface, there are some problems such as slow speed, instability and difficult operation, which lead to low development efficiency and seriously affect the progress of the project. This paper proposes a multi-core DSP software and hardware development platform with Gigabit Ethernet and PCIe as loading and debugging interfaces, including standardized hardware modules and software development environment. It has the advantages of easy reconfiguration, easy expansion, no longer relying on JTAG interface, compatibility with multiple software operating systems, and low resource occupation.Taking the multi-core DSP TMS320C 6678 as an example, this paper describes the key techniques in the development of the signal processing system composed of multi-chip DSPs, including COTS module, system architecture, hardware diagnoising, software loading, software debugging and so on. This platform can significantly reduce the application threshold and greatly improve the development efficiency.