A connection structure includes two connection interfaces and a connector. Each connection interface includes planar contacts arranged at a center and one or more concentric rings on a circuit board and first lock mechanisms arranged on a first casing. The connector includes a second casing including two open ends and second lock mechanisms arranged on the second casing and pins. Each pin includes two ends each exposed by one of the two open ends of the second casing, respectively. When the connector is plugged into the two connection interfaces at orientations relative to one another, the pins of the connector are in contact with the planar contacts of each connection interface so that the two connection interfaces are electrically connected, and the second lock mechanisms of the connector are interlocked with the first lock mechanisms of each connection interface so that the two connection interfaces are mechanically connected.