Connecting piece, PCB and electronic device

The utility model provides a connecting piece which comprises a circuit board and a wire harness, the circuit board comprises a switching circuit and a first connector, the first connector is used forconnecting an on-chip debugging simulator or programmer, a first end of the wire harness is connected with the circuit board, and a second end of the wire harness is provided with a second connector.Wherein the second connector is used for connecting a target PCB of the on-chip debugging simulator or programmer, and the switching circuit is used for switching connection contacts with different functions in the first connector to corresponding connection contacts of the second connector of the wire harness. The utility model also provides a PCB and an electronic device. According to the connecting piece, the PCB and the electronic device provided by the utility model, only one connector is arranged on the PCB, and the PCB can be connected with the debugging simulator on the chip and the programmer by changing the