A power system of an electric vehicle, comprising: a battery group; a battery heating circuit, connected to the battery group and configured to charge and discharge the battery group to heat the battery group; a battery management device, connected to the battery group and the battery heating circuit, the battery management device being configured to control the battery heating circuit to heat the battery group when a temperature of the battery group is lower than a first heating threshold and a residual electric quantity of the battery group is larger than a running electric quantity threshold, and to obtain a current throttle depth change rate of the electric vehicle in real time when the power system operates in a running heating mode, wherein the battery group is being heated by the battery heating circuit while the battery group is simultaneously supplying power to the electric vehicle; an electric distribution box, configured to distribute a voltage output by the battery group; a motor; a motor controller, connected to the motor and the electric distribution box respectively, comprising a first input terminal, a second input terminal and a pre-charging capacitor connected between the first input terminal and the second input terminal, and configured to supply power to the motor according to a control command and a voltage distributed by the electric distribution box; and an isolation inductor connected between the battery group and the electric distribution box; the power system characterized in that the battery management device is further configured to control the battery heating circuit to stop charging and discharging of the battery group to heat the battery group when the current throttle depth change rate reaches a preset throttle depth change rate threshold and to control the battery heating circuit to resume the charging and discharging of the battery group when the current throttle depth change rate is lower than the preset throttle depth change rate threshold, in the state that the charging and discharging of the battery group is stopped; and in that the isolation inductor and the pre-charging capacitor are configured to reduce the switching influence of the battery heating circuit on the motor controller, wherein the inductance of the isolation inductor is determined by the formula: T = 2 π LC, where T is the cycle of the circuit comprising the isolation inductor and the pre-charging capacitor. a battery group; a battery heating circuit, connected to the battery group and configured to charge and discharge the battery group to heat the battery group; a battery management device, connected to the battery group and the battery heating circuit, the battery management device being configured to control the battery heating circuit to heat the battery group when a temperature of the battery group is lower than a first heating threshold and a residual electric quantity of the battery group is larger than a running electric quantity threshold, and to obtain a current throttle depth change rate of the electric vehicle in real time when the power system operates in a running heating mode, wherein the battery group is being heated by the battery heating circuit while the battery group is simultaneously supplying power to the electric vehicle; an electric distribution box, configured to distribute a voltage output by the battery group; a motor; a motor controller, connected to the motor and the electric distribution box respectively, comprising a first input terminal, a second input terminal and a pre-charging capacitor connected between the first input terminal and the second input terminal, and configured to supply power to the motor according to a control command and a voltage distributed by the electric distribution box; and an isolation inductor connected between the battery group and the electric distribution box; the power system characterized in that the battery management device is further configured to control the battery heating circuit to stop charging and discharging of the battery group to heat the battery group when the current throttle depth change rate reaches a preset throttle depth change rate threshold and to control the battery heating circuit to resume the charging and discharging of the battery group when the current throttle depth change rate is lower than the preset throttle depth change rate threshold, in the state that the charging and discharging of the battery group is stopped; and in that the isolation inductor and the pre-charging capacitor are configured to reduce the switching influence of the battery heating circuit on the motor controller, wherein the inductance of the isolation inductor is determined by the formula: T = 2 π LC, where T is the cycle of the circuit comprising the isolation inductor and the pre-charging capacitor.