||This paper presents the design of a distributed multi-microcontroller based computing framework for UAV application. A DSPIC microcontroller (MCU) based system architecture is established first. The system contains three major parts, namely, sensing and attitude determination section, control section, and ground section. The sensing and attitude determination section consists of four circuit boards (master control board, slave control board, sensor board, and power supply board) of identical size (5 cm × 5 cm). The sensor board contains three axes inertial measurement unit, electronic compass unit, and a GPS receiver. The sensors and the DSPIC MCUs are connected via an I^2C (inter-integrated circuit) data bus with the DSPIC of the master control board acting as the master MCU. Modular design was used to combine the master and slave control boards to form the system's control section and to facilitate system expansion for accommodating additional avionics functions. UART interface was used for inter-section communication. Results of the design and simulation of a model-based flight control system with time delay were also included to demonstrate the success of the design of the distributed multi-MCU based flight control system.