The invention relates to a compressed air turbine DC generator system comprising an aerodynamic turbine engine; a DC generator which is used for generating direct current with the power output of the aerodynamic turbine engine acting as the driving input; and a control unit which is used for controlling the rotating speed of the aerodynamic turbine engine to generate the power output and adjusting the output current and/or the output voltage of the DC generator. The compressed air turbine DC generator system has the characteristics of miniaturization and high integration so that the disadvantages of low power density and high vibration noise of the internal combustion engine power generation system can be effectively overcome and the system has high industrial utilization value. The compressed air turbine DC generator system can be used as the auxiliary power supply in the development process of the electric automobile so that the problem of mileage anxiety of the pure electric automobile can be effectively solved.