The invention discloses a YMF series circular optical fiber electric connector in the technical field of electric connectors. The electric connector comprises a plug and a socket, wherein the plug comprises a head shell, a locking sleeve, an optical plug body, a first pressing plate, a corrugated spring, a check clamping spring, a check clamping ring, a first disk head screw, a straight sleeve, aconductive O-shaped ring, a crimping sleeve, an inner sleeve, a shielding ring, a sealing ring, a pressing ring, a sealing nut, a spring, a plug sealing cover, a first rubber pad, a first step rivet,a first connecting sheet, a first stainless steel wire rope, a first heat-shrinkable tube, a first connecting sleeve and a fixing ring. The electric connector can easily realize connection and disconnection of the plug and the socket by adopting a threaded connection mechanism and clockwise and anticlockwise rotating the head shell. The outer wall of the head shell is provided with five splines, and therefore the function of preventing misinsertion can be achieved. Good waterproof sealing performance is achieved after a headstock of the electric connector is inserted.