A wearable device (1) is provided. The wearable device includes a first functional module (100), at least one exposed contact (102), a second functional module (104), an ESD protection circuit (106) that converts an ESD input to an output voltage when the ESD input occurs, a detection module (108) that detects whether the exposed contact is connected to an external electronic module, a switch module (110) and a processing module (112). The switch module electrically connects the exposed contact and the second functional module when the exposed contact is connected to the external electronic module to perform a transmission behavior with the second functional module through the exposed contact. The switch module electrically connects the exposed contact and the ESD protection circuit when the exposed contact is not connected to the external electronic module. The processing module receives the input voltage to reset the first function module according to the input voltage. Fig. 1B
