The incoherent digital holographic microscopic imaging system based on the Michelson interferometer can be used to obtain the hologram of object under illumination of incoherent light. The incoherent digital holographic microscopic imaging system based on the Michelson interferometer is studied theoretically and experimentally. The point spread function of the system in the recording process has been calculated according to the scalar diffraction theory, and the specific expressions of lateral magnification and reconstruction distance of the system are deduced. A experimental light path of incoherent digital holographic microscopic imaging system based on the Michelson interferometer is built, and a CCD is used to record the holograms. A clear reconstruction image is obtained without conjugate image and zero-order image by the generalized phase-shifting digital holographic interferometry and via the angular spectrum algorithm. Furthermore, the incoherent holographic microscopic imaging of a resolution board and onion epidermal cells have been implemented, which proves the feasibility of the system. The imaging experiment of the resolution board shows that a lateral resolution as high as 512 lp/mm can be obtained. The system is able to present the characteristics of the three-dimensional structure of objects, which is verified by the imaging of the micron cleansing brush fur.