The invention provides an optical indicating device for the position of a landing gear. The optical indicating device comprises an upper locking lever (1) and a lower locking lever (2) of a down lock of the landing gear. The upper locking lever (1) and the lower locking lever (2) are mounted on the landing gear and are hinged to each other. The optical indicating device is characterized by also comprising a detectoscope (10), the detectoscope (10) is composed of an objective lens (5), an image-carrying fiber bundle (6) and an eye lens (7), the objective lens (5) end of the detectoscope (10) is mounted on a landing gear bulkhead plate (8) opposite to the upper locking lever (1) and the lower locking lever (2), the eye lens (7) end of the detectoscope (10) is mounted on a cabin bulkhead plate (9), an alignment mark (3) is provided on the upper locking lever (1) and the lower locking lever (2), the objective lens (5) images the target image of the alignment mark (3) on the end face of the image-carrying bundle, the light is then transmitted to the eye lens (7) through the image-carrying fiber bundle (6), and the target image can be observed through the eye lens (7).