Referring to FIG. 1 to FIG. 4, the insulating housing 10 includes a main portion 11 and a tongue portion 12 fastened to a front end of the main portion 11. A direction of the docking connector being inserted into the electrical connector 100 is defined as a front-to-rear direction, namely a longitudinal direction. Correspondingly, a transverse direction is defined as a direction perpendicular to the longitudinal direction. The main portion 11 includes a base portion 13, and a connecting portion 14 protruded frontward from a middle of a front surface of the base portion 13. Middles of a top surface and a bottom surface of the connecting portion 14 protrude oppositely to form two buckling blocks 17. Specifically, the main portion 11 includes an upper dielectric body 15 and a lower dielectric body 16 which are matched with each other and assembled together. The upper dielectric body 15 has an upper base portion 151, and an upper connecting portion 152 protruded frontward from a lower portion of a front surface of the upper base portion 151. Two opposite sides of a top surface of the upper connecting portion 152 are recessed inward to form two upper lacking grooves 153 penetrating through two opposite sides of a front surface of the upper connecting portion 152.