A current detecting apparatus, comprising a current sensor, a microcontroller unit, a primary positive circuit and a primary negative circuit, wherein: a positive electrode of a power battery pack to be tested is connected to a first terminal of the primary positive circuit, a negative electrode of the power battery pack is connected to a first terminal of the primary negative circuit, and the current sensor is connected in series between the negative electrode of the power battery pack and the first terminal of the primary negative circuit; the current sensor is configured for obtaining and outputting a voltage signal reflecting a current value of the power battery pack; the microcontroller unit is configured for collecting the voltage signal output from a signal terminal of the current sensor, implementing current conversion on the voltage signal, transmitting a detected current value, which is obtained by the current conversion, of the power battery pack and receiving a control command for controlling the primary positive circuit and the primary negative circuit to turn on or turn off, wherein the current detecting apparatus is characterized by further comprising an isolating and communicating module configured for electrically isolating the current sensor, the microcontroller unit, the primary positive circuit and the primary negative circuit from a low-voltage ide of the isolating and communicating module; receiving the detected current value from the microcontroller unit and forwarding the detected current value to a battery management unit; and receiving the control command from the battery management unit and forwarding the control command to the microcontroller unit, wherein the isolating and communicating module is further configured to forward the detected current value by: converting the detected current value of the power battery pack to current data meeting controller area network specifications; and outputting the current data meeting the CAN specifications by means of differential signal transmission, and wherein the microcontroller unit is located at a high-voltage side of the isolating and communicating module, and the battery management unit is located at the low-voltage side of the isolating and communicating module and configured to generate the control command based on the detected current value. a positive electrode of a power battery pack to be tested is connected to a first terminal of the primary positive circuit, a negative electrode of the power battery pack is connected to a first terminal of the primary negative circuit, and the current sensor is connected in series between the negative electrode of the power battery pack and the first terminal of the primary negative circuit; the current sensor is configured for obtaining and outputting a voltage signal reflecting a current value of the power battery pack; the microcontroller unit is configured for collecting the voltage signal output from a signal terminal of the current sensor, implementing current conversion on the voltage signal, transmitting a detected current value, which is obtained by the current conversion, of the power battery pack and receiving a control command for controlling the primary positive circuit and the primary negative circuit to turn on or turn off, wherein the current detecting apparatus is characterized by further comprising an isolating and communicating module configured for electrically isolating the current sensor, the microcontroller unit, the primary positive circuit and the primary negative circuit from a low-voltage ide of the isolating and communicating module; receiving the detected current value from the microcontroller unit and forwarding the detected current value to a battery management unit; and receiving the control command from the battery management unit and forwarding the control command to the microcontroller unit, wherein the isolating and communicating module is further configured to forward the detected current value by: converting the detected current value of the power battery pack to current data meeting controller area network specifications; and outputting the current data meeting the CAN specifications by means of differential signal transmission, and wherein the microcontroller unit is located at a high-voltage side of the isolating and communicating module, and the battery management unit is located at the low-voltage side of the isolating and communicating module and configured to generate the control command based on the detected current value. converting the detected current value of the power battery pack to current data meeting controller area network specifications; and outputting the current data meeting the CAN specifications by means of differential signal transmission, and wherein the microcontroller unit is located at a high-voltage side of the isolating and communicating module, and the battery management unit is located at the low-voltage side of the isolating and communicating module and configured to generate the control command based on the detected current value.