Foucs on the application requirement of airborne testing system on CAN bus, the scheme of CAN repeater design was proposed using STM32F105 as the master control CPU, and CAN bus message receiving with different transmitting rate was completed. The function of repeater was mainly stated，meanwhile the software and hardware design was introduced in detail. Data acquisition on CAN bus was carried on in the laboratory and airborne condition, where it was verified that the CAN repeater never disturbed the CAN bus and the testing result was correct with the 40m cable connection length between the airborne CAN bus and CAN repeater. The whole testing system worded so steadily and reliably that could satisfy the requirement of airborne CAN data test.