Abstract: A field-of-view stitching system including: a light source module for emitting a first beam; a light guiding element for splitting the first beam into a plurality of second beams and includes an incident surface, a first exit surface, and a plurality of second exit surfaces, the second beams propagate along an optical path of the first beam; and a plurality of light modulators, a number of the plurality of light modulators is the same as a total number of the first exit surface and the plurality of second exit surfaces, each of the plurality of light modulators is configured to receive and regularly reflect one of the plurality of second beams; the light guiding element is further configured to receive and combine the second beams reflected by the light modulators to form an illuminating light. A field-of-view stitching method, a biological sample identification device and method are also provided.