The invention discloses a microscopic imaging device and method for measuring microstructure defects on a surface of a semiconductor material. The testing device comprises a light source, a polarization modulation reflection difference system, a beam splitter prism, a scanning platform, a co-focusing microscopic system and a signal acquisition system. According to a photo-elastic effect principle and a crystal defect theory, although the microstructure defects on the surface of the semiconductor material have very small sizes, a very large strain distribution field relative to the microstructure defects is formed around the microstructure defects and the strain distribution field can generate an optical reflection anisotropic signal; the testing method can be used for measuring the optical reflection anisotropic signal of each measuring point around the microstructure defects so that an optical reflection anisotropic microscopic imaging pattern, which is close to the microstructure defects, related with the strain field and changed along with a space position, can be directly obtained, and furthermore, information including varieties, density, strain distribution and the like of the defects is obtained. With regard to characterization of the microstructure defects of the material, the microscopic imaging device and method, disclosed by the invention, have the advantages of simplicity and efficiency for operation, no damages, strong portability and the like.