Abstract: The present invention discloses a data transmission apparatus of a circuit breaker controller. The data transmission apparatus comprises: a first component having a first power supply and a second component having a second power supply. The first component and the second component share a storage device. The second component is connected to a main circuit of the circuit breaker controller. The second component collects parameters of the main circuit and stores the parameters in the storage device. The second power supply powers the second component and is powered by the main circuit. The first component is connected to a communication device. The first component establishes data transmission between the communication device and the storage device. The first power supply powers the first component and is powered by an external power supply. The second power supply is connected to the first power supply and transmits a control signal to the first power supply.