The invention relates to a semi-open type full circumferential coronagraph apparatus with a large field of view. The coronagraph apparatus comprises in sequence from left to right: an outer shielding body, an outer window, a heat collecting lens, an inner shielding body, an inner shielding body light-absorbing groove, an imaging system and a CCD camera. The outer shielding body and the inner shielding body are disposed on the optical axis of an optical path. The inner shielding body is positioned in an imaging position where the outer shielding body passes through an object lens unit. The coronagraph apparatus, as a whole, is of a semi-open square structure, and is reduced in size and weight. The heat collecting lens is a reflector with a square centrally-recessed structure, and the recessed surface of the centrally-recessed structure faces one side of the outer window. The heat collecting lens is arranged in an inclined manner. The lower end of the heat collecting lens goes toward one side of the outer window relative to the upper end of the heat collecting lens. Incident sun direct light is focused by the heat collecting lens outside the semi-open square structure, so the influence of scattered stray light on the surface of the heat collecting lens is reduced.