An electric connection structure includes a metal element (1) with an axle cavity and a metal element (2) with an axle head. The cross section edges of the hinge faces between the axle cavity and the axle head are in gradual spiral line type. As both the metal elements (1, 2) have larger corner, the hinge faces have larger space which will disappear when the metal elements rotate to be approximately horizontal, and the axle head and the axle cavity will attain compression force to be tightly combined in continuous rotation of the metal elements so as to have a large electric contact face, tight contact, non-loosen, and free maintenance.