An electronic device includes a circuit module with a circuit board, and a plug connector with a supporting base, several terminals, and an outer shell. The terminals are disposed at the supporting base, and connected to the circuit board. The outer shell surrounds the supporting base, and has two parallel horizontal plates. Two extending plates are extended from a front surface of one of the horizontal plates. A slot is formed among that horizontal plate and the two extending plates. Via these arrangements, the out shell of the plug connector has the slot, so that the deformation of the outer shell is more easily caused. Thus, even if the assembly tolerance between the plug connector and the socket connector is deviated, the force for plugging or unplugging the plug connector would not be too abnormal. That is because the outer shell can be easily deformed to compensate for the deviation.