The disclosure discloses a photoelectric detector and a photoelectric detection device, the photoelectric detector includes: a photosensitive active layer (100) including a first surface (1) and a second surface (2) opposite to each other; a first electrode (200) and a second electrode (300) located on the first surface (1) of the photosensitive active layer (100), and arranged spaced apart from each other; and a third electrode (400) located on the second surface (2) of the photosensitive active layer (100); where the first electrode (200) and the second electrode (300) respectively contact directly with the first surface (1) of the photosensitive active layer (100), and the third electrode (400) contacts directly with the second surface (2) of the photosensitive active layer (100). The photoelectric detector can improve the contrast between light current and dark current.