As the power proportion of Electric Vehicle (EV) charging and discharging station is gradually increasing in power system, the fault characteristics and protection configuration of EV charging and discharging station become more important to the safety of power grid and the station. Firstly, based on typical DC charging and discharging station, the station typology structure and the structure and control strategy of AC/DC converter and DC/DC converter are introduced, then the dynamic process of three-phase and inter-electrode short-circuit faults in the station is analyzed intensively, their main features are given, and the method of calculating fault voltages and currents is also discussed. The simulation model established in PSCAD/EMTDC verifies the correctness of the analysis. Finally, the protection setting of the charging and discharging station is analyzed. This work is supported by National Key Research and Development Project of China (No. 2016YFB0101900).