The key functions and advantage of Rural Intelligent Distribution Transformer Terminal are introduced, and a design scheme is presented based on OMAPL138 dualcore microprocessor. Data acquisition, signal processing and realtime control are realized by digital signal processer (DSP) core, while humanmachine interaction, data storage, communication and security protection are processed by advanced reduced instruction set computer machines (ARM) core through embedded Linux. Tasks are distributed clearly between DSP and ARM, and data exchange as well as resource sharing can be easily implemented within the chip. The design of terminal is based on bus interface and modular technology, which enhances its expansibility and flexibility. Hotplug of daughter boards and convenient system upgrade are supported by the terminal.