Rugged plug, rugged socket and operating method thereof

An operating method of a rugged plug, comprising:

• providing a rugged socket and a rugged plug plugged into the rugged socket, the rugged plug comprising an elastic inner sheath and a slidable rigid sheath movably sleeved over the elastic inner sheath, the elastic inner sheath comprising an elastic arm and a stop block, a hook laterally protruding from the elastic arm, the hook and the stop block protruding from side surfaces of the elastic inner sheath, and a tip of the hook being a curved surface, the hook being engaged with the rugged socket, the elastic arm forming a boss, and the slidable rigid sheath comprising an actuating curved surface abutting against the boss;
• moving the slidable rigid sheath in a first direction away from the hook, such that the actuating curved surface applies a force to the boss of the elastic arm to cause the hook to retract inward;
• and
• moving the slidable rigid sheath in a second direction toward the rugged socket, such that the slidable rigid sheath pushes the stop block of the elastic inner sheath, and after the hook abuts against the rugged socket, the hook retracts inward under a reaction force so as to allow the hook to engage with the rugged socket.