An electrical connector, a ring-like locking sheet with inner and outer teeth of which is fixed at the end of its plug connector; and a circumferential bulge, with trapezoid cross section which has an upslope, a flat top and a down-slope, is provided on the surface of the outer conductor of the socket connector. Therefore, in the process of connection, the inner teeth reach the max flexural deformation when go up along the slope to the flat top. When reach the down-slope, the deformed inner teeth gradually restore the original state in tangential direction of the down-slope, and finally stop at the down-slope or at the juncture of the down-slope and the flat top. The electrical connector according to the present invention can have a rigid zero clearance between the interfaces in connection, and at the same time can keep a very strong axial force. The RF coaxial connector according to the present invention has continuous impedance between the contact surfaces, reliable and stable contact, greatly reduced RF emission, as well as the same operating frequency, excellent RF performance and good passive intermodulation as those with threaded connection.