A magnetoresistive magnetic imaging sensor for identifying a magnetic image in a magnetic image detection plane, wherein the imaging sensor is a lateral detection mode image identification sensor; the lateral detection mode image identification sensor comprises several magnetoresistive sensor chips (2, 21) on a PCB, the PCB having a front surface (1) that is perpendicular to the magnetic image detection plane, and characterized by the several magnetoresistive sensor chips (2, 21) being located on the front surface of the PCB, and either: (i) one side of each of the several magnetoresistive sensor chips on the PCB corresponding to the lateral detection mode image identification sensor is cocked away from the front surface of the PCB, and the other side is obliquely stacked with one side of each of the adjacent magnetoresistive sensor chips; or (ii) the adjacent magnetoresistive sensor chips in the several magnetoresistive sensor chips on the PCB corresponding to the lateral detection mode image identification sensor are on-chip staggered and stacked; each of the several magnetoresistive sensor chips having a front surface (2) and a side face (2), each side face (2) of the several magnetoresistive sensor chips of the lateral detection mode image identification sensor being parallel to the magnetic image detection plane; and wherein the adjacent magnetoresistive sensor chips of each identification sensor are complementary to or intersect with each other in scanning detection areas along a scanning direction on the magnetic image detection plane; comprising a permanent magnet assembly, wherein magnetic sensing directions of the several magnetoresistive sensor chips of the lateral detection mode image identification sensor are perpendicular to the magnetic image detection plane; and wherein for the lateral detection mode image identification sensor, the permanent magnet assembly comprises a structure having an opening towards the magnetic image detection plane and formed by a permanent magnet (5) and an L-shaped soft magnet (5), which are located at the same side of the PCB, and the L-shaped soft magnet is located between the permanent magnet and the PCB, the permanent magnet is located on the bottom of the L-shaped soft magnet and the magnetization direction thereof is perpendicular to the magnetic image detection plane, and a side face of the L-shaped soft magnet is parallel to the PCB. wherein the imaging sensor is a lateral detection mode image identification sensor; the lateral detection mode image identification sensor comprises several magnetoresistive sensor chips (2, 21) on a PCB, the PCB having a front surface (1) that is perpendicular to the magnetic image detection plane, and characterized by the several magnetoresistive sensor chips (2, 21) being located on the front surface of the PCB, and either: (i) one side of each of the several magnetoresistive sensor chips on the PCB corresponding to the lateral detection mode image identification sensor is cocked away from the front surface of the PCB, and the other side is obliquely stacked with one side of each of the adjacent magnetoresistive sensor chips; or (ii) the adjacent magnetoresistive sensor chips in the several magnetoresistive sensor chips on the PCB corresponding to the lateral detection mode image identification sensor are on-chip staggered and stacked; (i) one side of each of the several magnetoresistive sensor chips on the PCB corresponding to the lateral detection mode image identification sensor is cocked away from the front surface of the PCB, and the other side is obliquely stacked with one side of each of the adjacent magnetoresistive sensor chips; or (ii) the adjacent magnetoresistive sensor chips in the several magnetoresistive sensor chips on the PCB corresponding to the lateral detection mode image identification sensor are on-chip staggered and stacked; each of the several magnetoresistive sensor chips having a front surface (2) and a side face (2), each side face (2) of the several magnetoresistive sensor chips of the lateral detection mode image identification sensor being parallel to the magnetic image detection plane; and wherein the adjacent magnetoresistive sensor chips of each identification sensor are complementary to or intersect with each other in scanning detection areas along a scanning direction on the magnetic image detection plane; comprising a permanent magnet assembly, wherein magnetic sensing directions of the several magnetoresistive sensor chips of the lateral detection mode image identification sensor are perpendicular to the magnetic image detection plane; and wherein for the lateral detection mode image identification sensor, the permanent magnet assembly comprises a structure having an opening towards the magnetic image detection plane and formed by a permanent magnet (5) and an L-shaped soft magnet (5), which are located at the same side of the PCB, and the L-shaped soft magnet is located between the permanent magnet and the PCB, the permanent magnet is located on the bottom of the L-shaped soft magnet and the magnetization direction thereof is perpendicular to the magnetic image detection plane, and a side face of the L-shaped soft magnet is parallel to the PCB.