A door closer capable of realizing self-control positioning has a cylindrical housing, a piston, a spring and a pull rod; the piston is built in the cylindrical housing and connected and fastened with one end of the pull rod; the pull rod is sheathed in the spring, and the two end parts of the spring respectively are in contact with a sealing lid of the piston and the cylindrical housing; the door closer further has a self-control positioning mechanism having a cylindrical outer sleeve a control part and a locking part; the cylindrical outer sleeve is connected and fastened with the cylindrical housing; the control part and the locking part are linked by a clutch and joined together; the locking part and the pull rod are linked by a clutch, and the pull rod is provided with a series of grooves which can be clasped with the locking part.