The invention relates to a connecting piece for automobile parts, in particular to a self-supporting hinge structure of a front cover of an automobile. The self-supporting hinge structure comprises two supporting hinges, wherein the front cover of the automobile is connected with an automobile body by the two supporting hinges; each supporting hinge comprises a fixed seat and a rotating arm which are hinged to each other; a ratchet wheel is arranged on each fixed seat; each rotating arm is hinged to a pawl capable of rotating; each pawl is matched with the corresponding ratchet wheel, and therefore, the front cover of the automobile is supported when opened to a maximum degree. The self-supporting hinge structure further comprises an unlocking handle, the unlocking handle is connected with the pawls on the two supporting hinges through a first inhaul cable and a second inhaul cable respectively, and the first inhaul cable and the second inhaul cable are stretched by the unlocking handle so as to separate the pawls from the ratchet wheels. By the self-supporting hinge structure, operation of a user can be simplified, when the front cover of the automobile is opened to the maximum degree, the front cover of the automobile can be supported through ratchet wheel and pawl mechanisms, and through the unlocking handle, supporting to the front cover can be released; and the self-supporting hinge structure of the front cover of the automobile is simple in structure, small in occupied space and suitable for automobile bodies with any configurations.