For a long time, the modular design has been the mainstream implementation method of missile-borne telemetry and control equipment. However, there is no uniform standard for information interaction between modules. The development unit defines it according to its own technical and signal characteristics. The way of definition directly affects or determines the difficulty of implementing missile-borne telemetry and control equipment. In order to develop an efficient internal interconnection technology for missile-borne telemetry and control equipment, so that the connection of modules is simpler and more efficient, and the degree of generalization is higher when the performance requirements of missile-borne telemetry and control equipment become more complex, this paper divides the missile-borne telemetry and control equipment into three core modules and function expansion modules, and defines an efficient module-level bus interface form and protocol. The bus includes the input and output of primary power supply, secondary power supply, and internal cross-linked signals. The signal interaction adopts the form of a half-duplex bus. Each module can access the bus online and edit the bus online. Through design and experimental verification, the bus design method simplifies the external interface of the missile-borne telemetry and control equipment, and enables convenient and efficient online generation of telemetry PCM (Pulse Code Modulation) code stream. The function expansion module can be freely added or reduced without increasing the hardware burden of the bus interface, making the missile-borne telemetry and control equipment highly versatile.