In this paper, we present a novel measurement-device-independent quantum protocol for Private Set Intersection/ Union Cardinality. This protocol takes weak coherent pulses in the BB84 polarization states as quantum resources, instead of ideal single photons, and only needs to perform Bell state identifications, instead of perfect Bell state measurements. With the current technology, our protocol has better feasibility and higher security than the related quantum protocol. Finally, we verify the correctness and feasibility of the proposed quantum protocol by circuit simulations in IBM Qiskit. [ABSTRACT FROM AUTHOR]