Good braking performance is an important guarantee for the vehicle driving. In the condition of frequent or prolonged braking, the overheating problem for the traditional mechanical braking device causes the recession of the braking performance, which is a prominent problem especially for the commercial vehicle perennial traveling in the mountains. Eddy current retarder can reduce the mechanical brake load as a kind of auxiliary braking device. Thus, the temperature of the mechanical braking device would not be too high, and the traveling safety of the vehicle can be ensured. But eddy current retarder would cause an enormous impact for automobile battery when it starts up and huge electricity energy would be consumed which means that more automotive batteries are needed. Considering above, a kind of self-excited eddy current retarder is developed in the paper. First, the design scheme for the self-excited eddy current retarder is illustrated based on the retarder's working principle, mechanical structure and the energy recovery features. Then, the mathematical model and the simulation model for the eddy current retarder are established by using MATLAB/Simulink. Finally, a prototype of the self-excited retarder is designed and manufactured based on the function combination of the disc-type eddy current retarder and permanent magnet generator. Simulation results show that the design of the self-excited eddy current retarder has a good energy characteristics and stability, and the test results verify that this design has a practical value.