Abstract: In this paper, a high-sensitivity orthogonal receiving system was designed based on finite-unit analysis to improve MPI signal detection sensitivity and magnetic field homogeneity for preclinical MPI of small animal imaging. The orthogonal receiving coil set was designed to add a new x-direction receiving coil, to improve the reception sensitivity and optimize imaging field of view area in z-direction. Simulation experiments, construction and calibration were carried out in the preclinical MPI platform with the high sensitivity orthogonal receiving systems to perform phantom imaging and small animal imaging experiments. Results show that the new orthogonal system can improve the image quality and contrast-noise rate effectively.