An optical disk drive includes a main body and a tray. The main body includes a housing and two rails disposed in the housing. The tray is slidably coupled to the two rails, and is operable to be switched between a first state and a second state. The tray is received in the housing in the first state, and protrudes out of the housing in the second state. The main body further includes a first resisting member. The tray includes a second resisting member. The first resisting member is adapted to apply a resisting force to the second resisting member in the first state to secure the tray. The first resisting member is away from the second resisting member in the second state.