The present application discloses an assembled unit having a locking mechanism, comprising a pair of lateral guide rails, a pair of class I plate members, a spine member and at least one eccentric rotation member. Each of the lateral guide rails is configured with a sliding groove along a direction of extension thereof. Both ends of each of the class I plate members can be inserted into the sliding groove of the corresponding lateral guide rail. Both ends of each of the lateral guide rails are respectively configured with an engaging structure. The spine member is configured with a raised sliding block along its direction of extension. On a surface of each of the type I plate members, a class I engaging slot is configured in a direction parallel to the lateral guide rail, the class I engaging slot opening at a side of the class I plate member.