A locking/unlocking structure of switch device includes a main body and an operation button. The main body is formed with a first stop section and a second stop section. The main body defines a chamber, in which a reaction drum and a wire connection module are assembled. A first elastic unit is disposed between the reaction drum and the main body for making the reaction drum positioned in an initial assembling position, (where the wire connection module is in a closed-circuit state). The reaction drum is assembled with a restriction unit and a second elastic unit. When the reaction drum moves in response to the motion of the operation button, the second elastic unit will force the restriction unit to move from the first stop section to the second stop section so as to control the wire connection module into an open-circuit state.