A probe card testing device includes a first sub-circuit board, a second sub-circuit board, a connecting structure layer, a fixing plate, a probe head and a plurality of conductive probes. The first sub-circuit board is electrically connected to the second sub-circuit board by the connecting structure layer. The fixing plate is disposed on the second sub-circuit board and includes an opening and an accommodating groove. The opening penetrates the fixing plate and exposes a plurality of pads on the second sub-circuit board. The accommodating groove is located on a side of the fixing plate relatively far away from the second sub-circuit board and communicates with the opening. The probe head is disposed in the accommodating groove of the fixing plate. The conductive probes are set on the probe head and in the opening of the fixing plate. One end of the conductive probes is in contact with the corresponding pads, respectively.