The invention discloses a leaky-wave dual-antenna system comprising a transmitting antenna array and a receiving antenna array. The transmitting antenna array comprises plural first microstrips and plural corresponding first differential circuits, and each of the first differential circuit matches the corresponding first microstrip by a L-type matching network; the receiving antenna array comprises plural second microstrips and plural corresponding second differential circuits, and each of the second differential circuit matches the corresponding second microstrip by a L-type matching network. A first end and a second end of each of the first differential circuits are respectively connected to the corresponding first microstrip; a third end and a fourth end of each of the second differential circuits are respectively connected to the corresponding second microstrip.