The invention discloses an internally occulting type imaging 
system of a transmission occulting 
coronagraph, and aims to solve the problem that 
stray light is difficult to restrain in the prior art. The 
system comprises an incident aperture diaphragm, an objective lens, an internally occulting body, a field lens, an Lyot diaphragm, an Lyot spot and a 
relay lens group which are mounted on an 
optical axis in a lens cone according to a sequential order after 
sunlight enters the lens cone, wherein the incident aperture diaphragm is located in the first surface position of the objective lens; the internally occulting body is located in the imaging focal plane position of the objective lens; the Lyot diaphragm is located in the imaging focal plane position, where the incident aperture diaphragm passes through, of the objective lens; the Lyot spot is located in the imaging focal plane position of the field lens; and after 
sunlight beams are focused by the objective lens, 
sunlight on a solar 
photosphere layer is shaded by the internally occulting body, and the obtained light beams are imaged on an 
image plane CCD (
charge coupled device) through the field lens and the 
relay lens group. The internally occulting type imaging 
system of the transmission ground-based 
coronagraph is provided with the internally occulting body and the Lyot spot, ghost images can be effectively blocked, and the 
stray light restraining capacity of the transmission ground-based 
coronagraph is further improved, therefore, the system can be used for observing sun 
corona.