In the past, the part of development of that is used for the military aviation target or reconnaissance is being extended to the range of application not only reconnaissance but also civilian industry as the introduction of the newest IT technology and the technical evolution. The Civilian low-cost UAV that is expected growth at the market of UAV in the world is accelerated to the extended applicability in the fields. However, The UAV study is recently focused on the Link and The Data bus because the main decision of the civilian UAV system configuration is not suitable to determinate the factory of price. In this paper is analysed the UAV data bus through the simulation in same condition both the CAN Bus which used the automobile industry and the MIL-STD-1553B which is used the aviation industry. As a comparison result, we identified that the CAN Bus of conventional configuration is possible to transmit the data without the need for a separate coupler equipment against the MIL-STD-1553B data. Thus, we identified that the CAN bus is capable to apply as a low-cost UAV internal data bus to optimize configuration and weight than 1553B.