Joint provided with centre

The utility model discloses a joint provided with a centre. The joint comprises a copper joint body, a copper tube, the centre and a copper nut, wherein a refrigerant through hole connected with the copper tube in a sealed manner is formed in the copper joint body; one end of the copper tube is fixedly connected with the copper joint body, a horn mouthexpanding outwards is arranged at the other end; the centre is arranged in the copper tube and faces towards one side ofthehorn mouth; a stepped hole consisting of a positioning hole, a chamfered hole and an inner threaded hole sequentially is formed in the copper nut, the chamfered hole and the horn mouth have surfaces capable of being attached to each other, and the copper tube is sleeved with the copper nut through the positioning hole. The joint provided with the centre is simple and convenient to use and can be connected and disconnected in one step, so that therefrigerant leakage is reduced, and the development cost is reduced; the centre is fixedly arrang