A connecting device includes at least one connector and a base. The connector includes a connecting slot for electrically connecting to an electronic device, a first pivoting structure disposed on the connecting slot, and a first positioning structure disposed on the connecting slot. The base includes at least one second pivoting structure pivoted to the first pivoting structure so that the connector is capable of rotating relative to the base, at least one second positioning structure for connecting with the first positioning structure so as to fix the connector and the base, and at least one pin set electrically connected to a circuit board and the connector so as to transmit signals between the circuit board and the electronic device.