Based on polarized interference principle, an optical system of near infrared spectroscopy with single optical path was proposed.For the tungsten halogen source coupled with optical fiber, the collimated and convergent systems using 90° off-axial parabolic mirror were designed. He-ne laser as source for sampling control was introduced, and the beams are combined and split with near infrared by a cold mirror. Two perpendicular Glan-thompson prisms are introduced as polarizers, within the compensated crystal and scanning wedge are set as optical phase compensator of the polarization interference. A near infrared polarization interference-based optical system was designed, whose wavelength band is from 800 nm to 1700 nm, theoretical spectrum resolution is better than 8 cm-1, and clear aperture is Φ10.4 mm.The results of quality evaluation show that the root mean square radius at marginal field of view according to the spot diagram is about 1.7 μm, the lateral chromatic aberration is 0.2 μm, and the geometric encircled energy at all the field of view has reached to 100% within a diameter of Φ14 μm.