Abstract: A USB type-C female connector includes an inner and an outer iron case, a terminal set, a plastic member, and a middle steel plate. The terminal set includes a terminal set A and a terminal set B. The terminal set A and terminal set B are in an upper and a lower terminal groove, respectively; the middle steel plate is in the middle steel plate slot. The plastic member is in the inner iron case; the inner iron case is in the outer iron case. The grounding terminal and the power terminal are formed of highly conductive copper material having a 0.20 to 0.30 mm thickness and a conductivity over 80%. The tongue plate area of the second terminal foot set A and second terminal foot set B facing the middle steel plate is thinned by 0.02 mm, improving impedance and optimizing insertion loss and return loss.