A self-ejectable port fixing device for contact connecting with a port having a port chip comprises: a casing having an opening; a receptacle chip provided in the casing, wherein the port chip is allowed to insert into the opening of the casing to contact with the receptacle chip; and an elastic unit and a locking unit which are provided in the casing, wherein the elastic unit is compressed directly or indirectly by the port so as to accumulate elastic potential energy as the port chip is getting closer to the receptacle chip, during the port chip being inserted into the casing through the opening of the casing to contact with the receptacle chip, when the port chip is in contact with the receptacle chip, the locking unit locks the port chip at this contact position, when the locking unit releases the lock, the elastic unit releases the elastic potential energy to push the port chip to be detached from the receptacle chip, wherein the port fixing device further comprises a stopper that is connected to the elastic unit, a handle end of the port pushes the stopper to compress the elastic unit as the port chip is getting closer to the receptacle chip during the port chip is inserted into the casing through the opening of the casing to contact with the receptacle chip, and when the locking unit releases the lock, the elastic unit releases the elastic potential energy so that the stopper pushes the handle end of the port in a direction away from a bottom wall of the casing, thus the port chip is detached from the receptacle chip, the stopper is arranged opposite to the receptacle chip, a side of the stopper and a side of the receptacle chip which face to each other are arranged in parallel and are spaced by a distance, the distance is equal to or slightly less than the width of the port chip and far less than the width of the handle end of the port, and said side of the receptacle chip which faces to the stopper is a side used for contacting with the port chip, the port fixing device characterized in that: the port fixing device further comprises a supporting unit that is provided in the casing for supporting the receptacle chip, wherein the supporting unit comprises a supporting rod, with a bottom end of the supporting rod being fixed on the bottom wall of the casing and the receptacle chip being provided on a top end of the supporting rod. a casing having an opening; a receptacle chip provided in the casing, wherein the port chip is allowed to insert into the opening of the casing to contact with the receptacle chip; and an elastic unit and a locking unit which are provided in the casing, wherein the elastic unit is compressed directly or indirectly by the port so as to accumulate elastic potential energy as the port chip is getting closer to the receptacle chip, during the port chip being inserted into the casing through the opening of the casing to contact with the receptacle chip, when the port chip is in contact with the receptacle chip, the locking unit locks the port chip at this contact position, when the locking unit releases the lock, the elastic unit releases the elastic potential energy to push the port chip to be detached from the receptacle chip, wherein the port fixing device further comprises a stopper that is connected to the elastic unit, a handle end of the port pushes the stopper to compress the elastic unit as the port chip is getting closer to the receptacle chip during the port chip is inserted into the casing through the opening of the casing to contact with the receptacle chip, and when the locking unit releases the lock, the elastic unit releases the elastic potential energy so that the stopper pushes the handle end of the port in a direction away from a bottom wall of the casing, thus the port chip is detached from the receptacle chip, the stopper is arranged opposite to the receptacle chip, a side of the stopper and a side of the receptacle chip which face to each other are arranged in parallel and are spaced by a distance, the distance is equal to or slightly less than the width of the port chip and far less than the width of the handle end of the port, and said side of the receptacle chip which faces to the stopper is a side used for contacting with the port chip, the port fixing device further comprises a supporting unit that is provided in the casing for supporting the receptacle chip, wherein the supporting unit comprises a supporting rod, with a bottom end of the supporting rod being fixed on the bottom wall of the casing and the receptacle chip being provided on a top end of the supporting rod.