In order to study the operation performance of mine direct current（DC） motor vehicle adopting pulse width modulation（PWM） chopper speed regulation system with different exciting mode

to explore more suitable exciting mode for minie DC locomotive operating conditions.A simulation model for PWM chopper speed regulation for electric locomotive is established

combined with the operating conditions of the mine DC electric locomotive

the operation performance（including starting performance

speed regulation performance and dynamic performance） in three different excitation modes are simulated and compared.The simulation results show that the DC locomotives separately exciting mode is more suitable for long distance transportation of rated load; DC locomotives series excitation mode is suitable for the occasion that frequent start and power requirements of fixed value.The research provides theoretical guidance and reference for the application and learning of the chopper speed regulation system of the mine DC locomotive.