A locking device includes a lock base configured to provide a locking position, and including a lock body having a surface provided with a lock groove recessed towards the inside of the lock body, the lock body being provided with a lock tongue groove and a lock tongue movably mounted in the lock tongue groove that is communicated with the lock groove; and a lock connecting rod movably connected with the lock base through the lock tongue, and including a rod member configured to drive the lock tongue to move under the action of an external force, the rod member being provided with an unlocking block on a side facing the lock base, and the unlocking block being configured as an arc protrusion formed outwardly by the rod member.