1. An image processing method of two-photon structured illumination point scanning microscopy, comprising the following steps: providing a laser light source, wherein the laser light source is focused onto a focal plane of a selected focal length, which is included in a detection target area of a sample-under-test, and the laser light source is a Near Infrared Pulsed Laser, meanwhile, the photon energy of the laser light source is half of the energy needed to let a molecule of the sample-under-test make a transition from ground state to a first excited state; performing scanning and recording, which is to use the laser light source, accompanied with an image recording system, to make a plurality of segmented scanning and image recording along two different directions respectively on the focal plane within the detection target area, so as to generate a plurality of structured illumination images of the detection target area; and performing image reconstruction, which is to perform reconstruction operation on the structured illumination images so as to generate microscopic image of the detection target area, including the sample-under-test.