Incident optical system used for near infrared spectrum perception node and working method thereof

An incident optical system used for a near infrared spectrum perception node comprises a near infrared light source, a plano-convex lens, a positive cylindrical mirror and a photosensitive component, wherein the plano-convex lens, the positive cylindrical mirror and the photosensitive component are successively arranged along an incident light propagation direction. Incident light successively passes through a convex surface side and a plane side of the plano-convex lens. The incident light successively passes through a convex cylindrical surface side and a plane side of the positive cylindrical mirror. Near infrared light finally enters into the photosensitive component. Optical beam shaping and energy gathering are performed on the near infrared light with a wave band of 1350nm to 1550nm. The system adopts the two lenses so as to shape a circular light beam at a pupil entrance into a linear light beam which is consistent with a size of a line array detector photosurface. Light energy losses are reduced, ove